Rename formula to equation

21 files changed, 102 insertions, 101 deletions

diff --git a/README.md b/README.md
index 73ad7002..22c3508d 100644
--- a/README.md
+++ b/README.md
@@ -49,8 +49,8 @@ Let's disect what's going on:
 - We insert a heading with the `= Heading` syntax. One equals sign creates a top
   level heading, two create a subheading and so on.
 
-- [Math formulas][math] are enclosed in dollar signs. By adding extra spaces
-  around the contents of a formula, we can put it into a separate block.
+- [Mathematical equations][math] are enclosed in dollar signs. By adding extra
+  spaces around the contents of a equation, we can put it into a separate block.
   Multi-letter identifiers are interpreted as Typst definitions and functions
   unless put into quotes. This way, we don't need backslashes for things like
   `floor` and `sqrt`. And `phi.alt` applies the `alt` modifier to the `phi` to
diff --git a/docs/src/reference/groups.yml b/docs/src/reference/groups.yml
index 476a2a26..04eed2ee 100644
--- a/docs/src/reference/groups.yml
+++ b/docs/src/reference/groups.yml
@@ -27,7 +27,7 @@
     "overbracket",
   ]
   description: |
-    Delimiters above or below parts of a formula.
+    Delimiters above or below parts of an equation.
 
     The braces and brackets further allow you to add an optional annotation
     below or above themselves.
@@ -44,7 +44,7 @@
     Subscript, superscripts, and limits.
 
     The `attach` function backs the `[$a_b^c$]` syntax that adds top and bottom
-    attachments to a part of a formula. Attachments can be displayed either as
+    attachments to a part of an equation. Attachments can be displayed either as
     sub/superscripts, or limits. Typst automatically decides which is more
     suitable depending on the base, but you can also control this manually with
     the `scripts` and `limits` functions.
diff --git a/docs/src/reference/syntax.md b/docs/src/reference/syntax.md
index 422c035f..b9063319 100644
--- a/docs/src/reference/syntax.md
+++ b/docs/src/reference/syntax.md
@@ -40,10 +40,11 @@ more about their syntax and usage.
 
 ## Math mode { #math }
 Math mode is a special markup mode that is used to typeset mathematical
-formulas. It is entered by wrapping a formula in `[$]` characters. The formula
-will be typeset into its own block if it starts and ends with at least one space
-(e.g. `[$ x^2 $]`). Inline math can be produced by omitting the whitespace (e.g.
-`[$x^2$]`). An overview over the syntax specific to math mode follows:
+formulas. It is entered by wrapping an equation in `[$]` characters. The
+equation will be typeset into its own block if it starts and ends with at least
+one space (e.g. `[$ x^2 $]`). Inline math can be produced by omitting the
+whitespace (e.g. `[$x^2$]`). An overview over the syntax specific to math mode
+follows:
 
 | Name                   | Example                  | See                      |
 | ---------------------- | ------------------------ | ------------------------ |
diff --git a/library/src/layout/container.rs b/library/src/layout/container.rs
index 0b7f7eb1..bdc147c3 100644
--- a/library/src/layout/container.rs
+++ b/library/src/layout/container.rs
@@ -261,7 +261,7 @@ pub struct BlockNode {
     ///
     /// ```example
     /// #set align(center)
-    /// #show math.formula: set block(above: 8pt, below: 16pt)
+    /// #show math.equation: set block(above: 8pt, below: 16pt)
     ///
     /// This sum of $x$ and $y$:
     /// $ x + y = z $
diff --git a/library/src/layout/mod.rs b/library/src/layout/mod.rs
index 4a38acb6..0ce292aa 100644
--- a/library/src/layout/mod.rs
+++ b/library/src/layout/mod.rs
@@ -50,7 +50,7 @@ use typst::diag::SourceResult;
 use typst::eval::Tracer;
 use typst::model::{applicable, realize, SequenceNode, StyleVecBuilder, StyledNode};
 
-use crate::math::{FormulaNode, LayoutMath};
+use crate::math::{EquationNode, LayoutMath};
 use crate::meta::DocumentNode;
 use crate::prelude::*;
 use crate::shared::BehavedBuilder;
@@ -245,9 +245,9 @@ impl<'a, 'v, 't> Builder<'a, 'v, 't> {
         mut content: &'a Content,
         styles: StyleChain<'a>,
     ) -> SourceResult<()> {
-        if content.can::<dyn LayoutMath>() && !content.is::<FormulaNode>() {
+        if content.can::<dyn LayoutMath>() && !content.is::<EquationNode>() {
             content =
-                self.scratch.content.alloc(FormulaNode::new(content.clone()).pack());
+                self.scratch.content.alloc(EquationNode::new(content.clone()).pack());
         }
 
         if let Some(styled) = content.to::<StyledNode>() {
@@ -491,7 +491,7 @@ impl<'a> ParBuilder<'a> {
             || content.is::<HNode>()
             || content.is::<LinebreakNode>()
             || content.is::<SmartQuoteNode>()
-            || content.to::<FormulaNode>().map_or(false, |node| !node.block(styles))
+            || content.to::<EquationNode>().map_or(false, |node| !node.block(styles))
             || content.is::<BoxNode>()
         {
             self.0.push(content.clone(), styles);
diff --git a/library/src/layout/par.rs b/library/src/layout/par.rs
index 8657d7fb..cef0d11c 100644
--- a/library/src/layout/par.rs
+++ b/library/src/layout/par.rs
@@ -7,7 +7,7 @@ use typst::model::StyledNode;
 
 use super::{BoxNode, HNode, Sizing, Spacing};
 use crate::layout::AlignNode;
-use crate::math::FormulaNode;
+use crate::math::EquationNode;
 use crate::prelude::*;
 use crate::text::{
     shape, LinebreakNode, Quoter, Quotes, ShapedText, SmartQuoteNode, SpaceNode, TextNode,
@@ -324,8 +324,8 @@ enum Segment<'a> {
     Text(usize),
     /// Horizontal spacing between other segments.
     Spacing(Spacing),
-    /// A math formula.
-    Formula(&'a FormulaNode),
+    /// A mathematical equation.
+    Equation(&'a EquationNode),
     /// A box with arbitrary content.
     Box(&'a BoxNode, bool),
     /// Metadata.
@@ -339,7 +339,7 @@ impl Segment<'_> {
             Self::Text(len) => len,
             Self::Spacing(_) => SPACING_REPLACE.len_utf8(),
             Self::Box(_, true) => SPACING_REPLACE.len_utf8(),
-            Self::Formula(_) | Self::Box(_, _) | Self::Meta => NODE_REPLACE.len_utf8(),
+            Self::Equation(_) | Self::Box(_, _) | Self::Meta => NODE_REPLACE.len_utf8(),
         }
     }
 }
@@ -597,9 +597,9 @@ fn collect<'a>(
                 full.push(if node.double(styles) { '"' } else { '\'' });
             }
             Segment::Text(full.len() - prev)
-        } else if let Some(node) = child.to::<FormulaNode>() {
+        } else if let Some(node) = child.to::<EquationNode>() {
             full.push(NODE_REPLACE);
-            Segment::Formula(node)
+            Segment::Equation(node)
         } else if let Some(node) = child.to::<BoxNode>() {
             let frac = node.width(styles).is_fractional();
             full.push(if frac { SPACING_REPLACE } else { NODE_REPLACE });
@@ -671,9 +671,9 @@ fn prepare<'a>(
                     items.push(Item::Fractional(v, None));
                 }
             },
-            Segment::Formula(formula) => {
+            Segment::Equation(equation) => {
                 let pod = Regions::one(region, Axes::splat(false));
-                let mut frame = formula.layout(vt, styles, pod)?.into_frame();
+                let mut frame = equation.layout(vt, styles, pod)?.into_frame();
                 frame.translate(Point::with_y(TextNode::baseline_in(styles)));
                 items.push(Item::Frame(frame));
             }
diff --git a/library/src/lib.rs b/library/src/lib.rs
index 0850faf4..14fea66d 100644
--- a/library/src/lib.rs
+++ b/library/src/lib.rs
@@ -211,7 +211,7 @@ fn items() -> LangItems {
             node.pack()
         },
         term_item: |term, description| layout::TermItem::new(term, description).pack(),
-        formula: |body, block| math::FormulaNode::new(body).with_block(block).pack(),
+        equation: |body, block| math::EquationNode::new(body).with_block(block).pack(),
         math_align_point: || math::AlignPointNode::new().pack(),
         math_delimited: |open, body, close| math::LrNode::new(open + body + close).pack(),
         math_attach: |base, bottom, top| {
diff --git a/library/src/math/mod.rs b/library/src/math/mod.rs
index 6df1d87a..c1e352d1 100644
--- a/library/src/math/mod.rs
+++ b/library/src/math/mod.rs
@@ -47,7 +47,7 @@ use crate::text::{
 /// Create a module with all math definitions.
 pub fn module() -> Module {
     let mut math = Scope::deduplicating();
-    math.define("formula", FormulaNode::id());
+    math.define("equation", EquationNode::id());
     math.define("text", TextNode::id());
 
     // Grouping.
@@ -106,7 +106,7 @@ pub fn module() -> Module {
     Module::new("math").with_scope(math)
 }
 
-/// A mathematical formula.
+/// A mathematical equation.
 ///
 /// Can be displayed inline with text or as a separate block.
 ///
@@ -125,25 +125,25 @@ pub fn module() -> Module {
 ///
 /// ## Syntax
 /// This function also has dedicated syntax: Write mathematical markup within
-/// dollar signs to create a formula. Starting and ending the formula with at
+/// dollar signs to create an equation. Starting and ending the equation with at
 /// least one space lifts it into a separate block that is centered
 /// horizontally. For more details about math syntax, see the
 /// [main math page]($category/math).
 ///
-/// Display: Formula
+/// Display: Equation
 /// Category: math
 #[node(Show, Finalize, Layout, LayoutMath)]
-pub struct FormulaNode {
-    /// Whether the formula is displayed as a separate block.
+pub struct EquationNode {
+    /// Whether the equation is displayed as a separate block.
     #[default(false)]
     pub block: bool,
 
-    /// The content of the formula.
+    /// The contents of the equation.
     #[required]
     pub body: Content,
 }
 
-impl Show for FormulaNode {
+impl Show for EquationNode {
     fn show(&self, _: &mut Vt, styles: StyleChain) -> SourceResult<Content> {
         let mut realized = self.clone().pack().guarded(Guard::Base(NodeId::of::<Self>()));
         if self.block(styles) {
@@ -153,7 +153,7 @@ impl Show for FormulaNode {
     }
 }
 
-impl Finalize for FormulaNode {
+impl Finalize for EquationNode {
     fn finalize(&self, realized: Content, _: StyleChain) -> Content {
         realized
             .styled(TextNode::set_weight(FontWeight::from_number(450)))
@@ -163,7 +163,7 @@ impl Finalize for FormulaNode {
     }
 }
 
-impl Layout for FormulaNode {
+impl Layout for EquationNode {
     fn layout(
         &self,
         vt: &mut Vt,
@@ -209,7 +209,7 @@ pub trait LayoutMath {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()>;
 }
 
-impl LayoutMath for FormulaNode {
+impl LayoutMath for EquationNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
         self.body().layout_math(ctx)
     }
diff --git a/library/src/math/op.rs b/library/src/math/op.rs
index bd81aa0e..dae43c3a 100644
--- a/library/src/math/op.rs
+++ b/library/src/math/op.rs
@@ -2,7 +2,7 @@ use typst::eval::Scope;
 
 use super::*;
 
-/// A text operator in a math formula.
+/// A text operator in an equation.
 ///
 /// ## Example
 /// ```example
diff --git a/library/src/math/style.rs b/library/src/math/style.rs
index 60bad6a5..a3383a0c 100644
--- a/library/src/math/style.rs
+++ b/library/src/math/style.rs
@@ -11,7 +11,7 @@ use super::*;
 /// Category: math
 #[node(LayoutMath)]
 pub struct BoldNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -36,7 +36,7 @@ impl LayoutMath for BoldNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct UprightNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -58,7 +58,7 @@ impl LayoutMath for UprightNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct ItalicNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -80,7 +80,7 @@ impl LayoutMath for ItalicNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct SerifNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -105,7 +105,7 @@ impl LayoutMath for SerifNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct SansNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -130,7 +130,7 @@ impl LayoutMath for SansNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct CalNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -155,7 +155,7 @@ impl LayoutMath for CalNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct FrakNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -180,7 +180,7 @@ impl LayoutMath for FrakNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct MonoNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -210,7 +210,7 @@ impl LayoutMath for MonoNode {
 /// Category: math
 #[node(LayoutMath)]
 pub struct BbNode {
-    /// The piece of formula to style.
+    /// The content to style.
     #[required]
     pub body: Content,
 }
@@ -224,7 +224,7 @@ impl LayoutMath for BbNode {
     }
 }
 
-/// Text properties in a formula.
+/// Text properties in math.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct MathStyle {
     /// The style variant to select.
@@ -298,7 +298,7 @@ impl MathStyle {
     }
 }
 
-/// The size of elements in a formula.
+/// The size of elements in an equation.
 ///
 /// See the TeXbook p. 141.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
diff --git a/src/eval/library.rs b/src/eval/library.rs
index 0e0b38aa..485a766b 100644
--- a/src/eval/library.rs
+++ b/src/eval/library.rs
@@ -77,18 +77,18 @@ pub struct LangItems {
     pub enum_item: fn(number: Option<NonZeroUsize>, body: Content) -> Content,
     /// An item in a term list: `/ Term: Details`.
     pub term_item: fn(term: Content, description: Content) -> Content,
-    /// A mathematical formula: `$x$`, `$ x^2 $`.
-    pub formula: fn(body: Content, block: bool) -> Content,
-    /// An alignment point in a formula: `&`.
+    /// A mathematical equation: `$x$`, `$ x^2 $`.
+    pub equation: fn(body: Content, block: bool) -> Content,
+    /// An alignment point in math: `&`.
     pub math_align_point: fn() -> Content,
-    /// Matched delimiters surrounding math in a formula: `[x + y]`.
+    /// Matched delimiters in math: `[x + y]`.
     pub math_delimited: fn(open: Content, body: Content, close: Content) -> Content,
-    /// A base with optional attachments in a formula: `a_1^2`.
+    /// A base with optional attachments in math: `a_1^2`.
     pub math_attach:
         fn(base: Content, bottom: Option<Content>, top: Option<Content>) -> Content,
     /// A base with an accent: `arrow(x)`.
     pub math_accent: fn(base: Content, accent: char) -> Content,
-    /// A fraction in a formula: `x/2`.
+    /// A fraction in math: `x/2`.
     pub math_frac: fn(num: Content, denom: Content) -> Content,
     /// Dispatch a method on a library value.
     pub library_method: fn(
@@ -126,7 +126,7 @@ impl Hash for LangItems {
         self.list_item.hash(state);
         self.enum_item.hash(state);
         self.term_item.hash(state);
-        self.formula.hash(state);
+        self.equation.hash(state);
         self.math_align_point.hash(state);
         self.math_delimited.hash(state);
         self.math_attach.hash(state);
diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 27ed85e5..74c5f0b3 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -426,7 +426,7 @@ impl Eval for ast::Expr {
             Self::List(v) => v.eval(vm).map(Value::Content),
             Self::Enum(v) => v.eval(vm).map(Value::Content),
             Self::Term(v) => v.eval(vm).map(Value::Content),
-            Self::Formula(v) => v.eval(vm).map(Value::Content),
+            Self::Equation(v) => v.eval(vm).map(Value::Content),
             Self::Math(v) => v.eval(vm).map(Value::Content),
             Self::MathIdent(v) => v.eval(vm),
             Self::MathAlignPoint(v) => v.eval(vm).map(Value::Content),
@@ -626,13 +626,13 @@ impl Eval for ast::TermItem {
     }
 }
 
-impl Eval for ast::Formula {
+impl Eval for ast::Equation {
     type Output = Content;
 
     fn eval(&self, vm: &mut Vm) -> SourceResult<Self::Output> {
         let body = self.body().eval(vm)?;
         let block = self.block();
-        Ok((vm.items.formula)(body, block))
+        Ok((vm.items.equation)(body, block))
     }
 }
 
diff --git a/src/eval/scope.rs b/src/eval/scope.rs
index d1590063..d4338b5c 100644
--- a/src/eval/scope.rs
+++ b/src/eval/scope.rs
@@ -45,7 +45,7 @@ impl<'a> Scopes<'a> {
             .ok_or("unknown variable")?)
     }
 
-    /// Try to access a variable immutably from within a math formula.
+    /// Try to access a variable immutably in math.
     pub fn get_in_math(&self, var: &str) -> StrResult<&Value> {
         Ok(std::iter::once(&self.top)
             .chain(self.scopes.iter().rev())
diff --git a/src/ide/complete.rs b/src/ide/complete.rs
index 66590160..4a1f0216 100644
--- a/src/ide/complete.rs
+++ b/src/ide/complete.rs
@@ -237,13 +237,13 @@ fn markup_completions(ctx: &mut CompletionContext) {
     ctx.snippet_completion(
         "math (inline)",
         "$${x}$",
-        "Inserts an inline-level mathematical formula.",
+        "Inserts an inline-level mathematical equation.",
     );
 
     ctx.snippet_completion(
         "math (block)",
         "$ ${sum_x^2} $",
-        "Inserts a block-level mathematical formula.",
+        "Inserts a block-level mathematical equation.",
     );
 }
 
@@ -251,7 +251,7 @@ fn markup_completions(ctx: &mut CompletionContext) {
 fn complete_math(ctx: &mut CompletionContext) -> bool {
     if !matches!(
         ctx.leaf.parent_kind(),
-        Some(SyntaxKind::Formula)
+        Some(SyntaxKind::Equation)
             | Some(SyntaxKind::Math)
             | Some(SyntaxKind::MathFrac)
             | Some(SyntaxKind::MathAttach)
@@ -935,10 +935,10 @@ impl<'a> CompletionContext<'a> {
 
     /// Add completions for all font families.
     fn font_completions(&mut self) {
-        let formula = self.before[self.cursor.saturating_sub(25)..].contains("formula");
+        let equation = self.before[self.cursor.saturating_sub(25)..].contains("equation");
         for (family, iter) in self.world.book().families() {
             let detail = summarize_font_family(iter);
-            if !formula || family.contains("Math") {
+            if !equation || family.contains("Math") {
                 self.value_completion(
                     None,
                     &Value::Str(family.into()),
@@ -1121,7 +1121,7 @@ impl<'a> CompletionContext<'a> {
 
         let in_math = matches!(
             self.leaf.parent_kind(),
-            Some(SyntaxKind::Formula)
+            Some(SyntaxKind::Equation)
                 | Some(SyntaxKind::Math)
                 | Some(SyntaxKind::MathFrac)
                 | Some(SyntaxKind::MathAttach)
diff --git a/src/ide/highlight.rs b/src/ide/highlight.rs
index 6214328b..e948975b 100644
--- a/src/ide/highlight.rs
+++ b/src/ide/highlight.rs
@@ -27,9 +27,9 @@ pub enum Tag {
     ListMarker,
     /// A term in a term list.
     ListTerm,
-    /// The delimiters of a math formula.
+    /// The delimiters of an equation.
     MathDelimiter,
-    /// An operator with special meaning in a math formula.
+    /// An operator with special meaning in an equation.
     MathOperator,
     /// A keyword.
     Keyword,
@@ -138,7 +138,7 @@ pub fn highlight(node: &LinkedNode) -> Option<Tag> {
         SyntaxKind::EnumMarker => Some(Tag::ListMarker),
         SyntaxKind::TermItem => None,
         SyntaxKind::TermMarker => Some(Tag::ListMarker),
-        SyntaxKind::Formula => None,
+        SyntaxKind::Equation => None,
 
         SyntaxKind::Math => None,
         SyntaxKind::MathIdent => highlight_ident(node),
diff --git a/src/syntax/ast.rs b/src/syntax/ast.rs
index 59205efb..9b76d292 100644
--- a/src/syntax/ast.rs
+++ b/src/syntax/ast.rs
@@ -112,19 +112,19 @@ pub enum Expr {
     Enum(EnumItem),
     /// An item in a term list: `/ Term: Details`.
     Term(TermItem),
-    /// A math formula: `$x$`, `$ x^2 $`.
-    Formula(Formula),
-    /// A math formula: `$x$`, `$ x^2 $`.
+    /// A mathematical equation: `$x$`, `$ x^2 $`.
+    Equation(Equation),
+    /// The contents of a mathematical equation: `x^2 + 1`.
     Math(Math),
-    /// An identifier in a math formula: `pi`.
+    /// An identifier in math: `pi`.
     MathIdent(MathIdent),
-    /// An alignment point in a math formula: `&`.
+    /// An alignment point in math: `&`.
     MathAlignPoint(MathAlignPoint),
-    /// Matched delimiters surrounding math in a formula: `[x + y]`.
+    /// Matched delimiters in math: `[x + y]`.
     MathDelimited(MathDelimited),
-    /// A base with optional attachments in a formula: `a_1^2`.
+    /// A base with optional attachments in math: `a_1^2`.
     MathAttach(MathAttach),
-    /// A fraction in a math formula: `x/2`.
+    /// A fraction in math: `x/2`.
     MathFrac(MathFrac),
     /// An identifier: `left`.
     Ident(Ident),
@@ -214,7 +214,7 @@ impl AstNode for Expr {
             SyntaxKind::ListItem => node.cast().map(Self::List),
             SyntaxKind::EnumItem => node.cast().map(Self::Enum),
             SyntaxKind::TermItem => node.cast().map(Self::Term),
-            SyntaxKind::Formula => node.cast().map(Self::Formula),
+            SyntaxKind::Equation => node.cast().map(Self::Equation),
             SyntaxKind::Math => node.cast().map(Self::Math),
             SyntaxKind::MathIdent => node.cast().map(Self::MathIdent),
             SyntaxKind::MathAlignPoint => node.cast().map(Self::MathAlignPoint),
@@ -273,7 +273,7 @@ impl AstNode for Expr {
             Self::List(v) => v.as_untyped(),
             Self::Enum(v) => v.as_untyped(),
             Self::Term(v) => v.as_untyped(),
-            Self::Formula(v) => v.as_untyped(),
+            Self::Equation(v) => v.as_untyped(),
             Self::Math(v) => v.as_untyped(),
             Self::MathIdent(v) => v.as_untyped(),
             Self::MathAlignPoint(v) => v.as_untyped(),
@@ -696,17 +696,17 @@ impl TermItem {
 }
 
 node! {
-    /// A math formula: `$x$`, `$ x^2 $`.
-    Formula
+    /// A mathemathical equation: `$x$`, `$ x^2 $`.
+    Equation
 }
 
-impl Formula {
+impl Equation {
     /// The contained math.
     pub fn body(&self) -> Math {
         self.0.cast_first_match().unwrap_or_default()
     }
 
-    /// Whether the formula should be displayed as a separate block.
+    /// Whether the equation should be displayed as a separate block.
     pub fn block(&self) -> bool {
         let is_space = |node: Option<&SyntaxNode>| {
             node.map(SyntaxNode::kind) == Some(SyntaxKind::Space)
@@ -716,7 +716,7 @@ impl Formula {
 }
 
 node! {
-    /// Math markup.
+    /// The contents of a mathematical equation: `x^2 + 1`.
     Math
 }
 
@@ -728,7 +728,7 @@ impl Math {
 }
 
 node! {
-    /// An identifier in a math formula: `pi`.
+    /// An identifier in math: `pi`.
     MathIdent
 }
 
@@ -758,12 +758,12 @@ impl Deref for MathIdent {
 }
 
 node! {
-    /// An alignment point in a formula: `&`.
+    /// An alignment point in math: `&`.
     MathAlignPoint
 }
 
 node! {
-    /// Matched delimiters surrounding math in a formula: `[x + y]`.
+    /// Matched delimiters in math: `[x + y]`.
     MathDelimited
 }
 
@@ -785,7 +785,7 @@ impl MathDelimited {
 }
 
 node! {
-    /// A base with optional attachments in a formula: `a_1^2`.
+    /// A base with optional attachments in math: `a_1^2`.
     MathAttach
 }
 
@@ -813,7 +813,7 @@ impl MathAttach {
 }
 
 node! {
-    /// A fraction in a formula: `x/2`
+    /// A fraction in math: `x/2`
     MathFrac
 }
 
diff --git a/src/syntax/kind.rs b/src/syntax/kind.rs
index ce3ae744..869d77af 100644
--- a/src/syntax/kind.rs
+++ b/src/syntax/kind.rs
@@ -56,18 +56,18 @@ pub enum SyntaxKind {
     TermItem,
     /// Introduces a term item: `/`.
     TermMarker,
-    /// A mathematical formula: `$x$`, `$ x^2 $`.
-    Formula,
+    /// A mathematical equation: `$x$`, `$ x^2 $`.
+    Equation,
 
-    /// Mathematical markup.
+    /// The contents of a mathematical equation: `x^2 + 1`.
     Math,
     /// An identifier in math: `pi`.
     MathIdent,
     /// An alignment point in math: `&`.
     MathAlignPoint,
-    /// Matched delimiters surrounding math in a formula: `[x + y]`.
+    /// Matched delimiters in math: `[x + y]`.
     MathDelimited,
-    /// A base with optional attachments in a formula: `a_1^2`.
+    /// A base with optional attachments in math: `a_1^2`.
     MathAttach,
     /// A fraction in math: `x/2`.
     MathFrac,
@@ -100,7 +100,7 @@ pub enum SyntaxKind {
     Star,
     /// Toggles emphasized text and indicates a subscript in math: `_`.
     Underscore,
-    /// Starts and ends a math formula: `$`.
+    /// Starts and ends a mathematical equation: `$`.
     Dollar,
     /// The unary plus and binary addition operator: `+`.
     Plus,
@@ -342,7 +342,7 @@ impl SyntaxKind {
             Self::EnumMarker => "enum marker",
             Self::TermItem => "term list item",
             Self::TermMarker => "term marker",
-            Self::Formula => "math formula",
+            Self::Equation => "equation",
             Self::Math => "math",
             Self::MathIdent => "math identifier",
             Self::MathAlignPoint => "math alignment point",
diff --git a/src/syntax/parser.rs b/src/syntax/parser.rs
index 127a89d5..c44e8cb3 100644
--- a/src/syntax/parser.rs
+++ b/src/syntax/parser.rs
@@ -114,7 +114,7 @@ fn markup_expr(p: &mut Parser, at_start: &mut bool) {
         SyntaxKind::EnumMarker if *at_start => enum_item(p),
         SyntaxKind::TermMarker if *at_start => term_item(p),
         SyntaxKind::RefMarker => reference(p),
-        SyntaxKind::Dollar => formula(p),
+        SyntaxKind::Dollar => equation(p),
 
         SyntaxKind::LeftBracket
         | SyntaxKind::RightBracket
@@ -213,14 +213,14 @@ fn whitespace_line(p: &mut Parser) {
     }
 }
 
-fn formula(p: &mut Parser) {
+fn equation(p: &mut Parser) {
     let m = p.marker();
     p.enter(LexMode::Math);
     p.assert(SyntaxKind::Dollar);
     math(p, |kind| kind == SyntaxKind::Dollar);
     p.expect(SyntaxKind::Dollar);
     p.exit();
-    p.wrap(m, SyntaxKind::Formula);
+    p.wrap(m, SyntaxKind::Equation);
 }
 
 fn math(p: &mut Parser, mut stop: impl FnMut(SyntaxKind) -> bool) {
@@ -631,7 +631,7 @@ fn code_primary(p: &mut Parser, atomic: bool) {
         SyntaxKind::LeftBrace => code_block(p),
         SyntaxKind::LeftBracket => content_block(p),
         SyntaxKind::LeftParen => with_paren(p),
-        SyntaxKind::Dollar => formula(p),
+        SyntaxKind::Dollar => equation(p),
         SyntaxKind::Let => let_binding(p),
         SyntaxKind::Set => set_rule(p),
         SyntaxKind::Show => show_rule(p),
diff --git a/tests/typ/compiler/content-field.typ b/tests/typ/compiler/content-field.typ
index 0eeee458..b67c090d 100644
--- a/tests/typ/compiler/content-field.typ
+++ b/tests/typ/compiler/content-field.typ
@@ -1,6 +1,6 @@
 // Integrated test for content fields.
 
-#let compute(formula, ..vars) = {
+#let compute(equation, ..vars) = {
   let vars = vars.named()
   let f(node) = {
     let func = node.func()
@@ -28,14 +28,14 @@
         .fold(0, (sum, v) => sum + v)
     }
   }
-  let result = f(formula.body)
+  let result = f(equation.body)
   [With ]
   vars
     .pairs()
     .map(p => $#p.first() = #p.last()$)
     .join(", ", last: " and ")
   [ we have:]
-  $ formula = result $
+  $ equation = result $
 }
 
 #compute($x y + y^2$, x: 2, y: 3)
diff --git a/tests/typ/math/content.typ b/tests/typ/math/content.typ
index 2e680671..a36960ff 100644
--- a/tests/typ/math/content.typ
+++ b/tests/typ/math/content.typ
@@ -10,7 +10,7 @@ $ sum_(i=#emoji.apple)^#emoji.apple.red i + monkey/2 $
 $ x := #table(columns: 2)[x][y]/mat(1, 2, 3)
      = #table[A][B][C] $
 ---
-// Test non-formula math directly in content.
+// Test non-equation math directly in content.
 #math.attach($a$, top: [b])
 
 ---
diff --git a/tests/typ/math/style.typ b/tests/typ/math/style.typ
index 017c62f2..45704d80 100644
--- a/tests/typ/math/style.typ
+++ b/tests/typ/math/style.typ
@@ -26,5 +26,5 @@ $text(#red, "time"^2) + sqrt("place")$
 
 ---
 // Test different font.
-#show math.formula: set text(font: "Fira Math")
+#show math.equation: set text(font: "Fira Math")
 $ v := vec(1 + 2, 2 - 4, sqrt(3), arrow(x)) + 1 $