Reduced code duplication, added other environments.

Added the remark, corrolary, and example environments.

source/template.typ

@@ -3,15 +3,23 @@
 
 // Constants.
 
+// The QED sign - a square drawn with four strokes.
+#let qed = [$square.stroked$]
+
 // Language-specific constants.
 #let lang = "fr"
+
+// Environments name.
 #let outline-title = [Table des matières]
-#let abstract-begin = "Résumé"
-#let theorem-begin = "Théorème"
-#let proposition-begin = "Propostition"
-#let lemma-begin = "Lemme"
-#let definition-begin = "Définition"
-#let proof-begin = "Démonstration"
+#let abstract-text = "Résumé"
+#let proposition-text = "Propostition"
+#let lemma-text = "Lemme"
+#let theorem-text = "Théorème"
+#let corrolary-text = "Théorème"
+#let definition-text = "Définition"
+#let remark-text = "Remarque"
+#let example-text = "Exemple"
+#let proof-text = "Démonstration"
 
 // Number the equations starting with the heading hierarchy before them.
 // E.g. if we are looking at the 6th equation in the 4th subheading
@@ -19,84 +27,52 @@
 #let numbering-equation(equation) = [(#counter(heading).display()#equation)]
 #let numbered-equation(body) = math.equation(numbering: numbering-equation, block: true)[#body]
 
-// The QED sign - a square drawn with four strokes.
-#let qed = [$square.stroked$]
-
 // Functions.
 
-// Empathize text by putting it in a very light filled gray box.
-#let block-emph-fill(body, intensity: 10) = {
-  rect(fill: rgb(0, 0, 0, intensity), width: 100%, radius: 1pt)[#body]
+#let block-emph(body, way: "") = {
+  if way == "fill" {
+    // Empathize text by putting it in a very light filled gray box.
+    rect(fill: rgb(0, 0, 0, 10), width: 100%, radius: 1pt)[#body]
+  } else if way == "outline" {
+    // Empathize text by putting it in a very light gray box.
+    rect(stroke: rgb(0, 0, 0, 18) + 4pt, width: 100%, radius: 1pt)[#body]
+  } else {
+    [#body]
+  }
 }
 
-// Empathize text by putting it in a very light gray box.
-#let block-emph-outline(body, intensity: 18) = {
-  rect(stroke: rgb(0, 0, 0, intensity) + 4pt, width: 100%, radius: 1pt)[#body]
-}
-
-// Create a theorem environment.
-// We create a counter to be able to index the theorem.
-#let theorem-counter = counter("theorem")
-
-// The `name` named variable allows us to give a name to a theorem.
-// E.g, `#theorem("Euclid")[<...>]` gives [#theorem-begin (Euclid). <...>].
-#let theorem(body, name: "") = {
-  theorem-counter.step()
+// The `name` named variable allows us to give a name to be displayed instead of the numbers.
+#let math-block(body, name: "", kind: "", emphasis: "bold", decoration: "fill") = {
+  // We create a counter to be able to index the environment.
+  let current-counter = counter(kind)
 
   let id = if name == "" {
-    counter(heading).display() + theorem-counter.display()
+    current-counter.step()
+    counter(heading).display() + current-counter.display()
   } else {
     "(" + name + ")"
   }
 
-  block-emph-fill[*#theorem-begin #id.* #body]
-}
-
-// Behaves like theorem, but with a different counter.
-#let proposition-counter = counter("proposition")
-#let proposition(body, name: "") = {
-  proposition-counter.step()
-
-  let id = if name == "" {
-    counter(heading).display() + proposition-counter.display()
+  if emphasis == "bold" {
+    block-emph(way: decoration)[*#kind #id.* #body]
+  } else if emphasis == "italics" {
+    block-emph(way: decoration)[_#kind #id._ #body]
   } else {
-    "(" + name + ")"
+    block-emph(way: decoration)[#kind #id. #body]
   }
-
-  block-emph-fill[*#proposition-begin #id.* #body]
 }
 
-// Behaves like theorem, but with a different counter.
-#let lemma-counter = counter("lemma")
-#let lemma(body, name: "") = {
-  lemma-counter.step()
-  let id = if name == "" {
-    counter(heading).display() + lemma-counter.display()
-  } else {
-    "(" + name + ")"
-  }
-
-  block-emph-fill[*#lemma-begin #id.* #body]
-}
-
-// Behaves like theorem, but with a different counter and a different emphasis.
-#let definition-counter = counter("definition")
-#let definition(body, name: "") = {
-  definition-counter.step()
-  let id = if name == "" {
-    counter(heading).display() + definition-counter.display()
-  } else {
-    "(" + name + ")"
-  }
-
-  block-emph-outline[_#definition-begin #id._ #body]
-}
+#let proposition(body, name: "") = math-block(body, name: name, kind: proposition-text)
+#let lemma(body, name: "") = math-block(body, name: name, kind: lemma-text)
+#let theorem(body, name: "") = math-block(body, name: name, kind: lemma-text)
+#let corrolary(body, name: "") = math-block(body, name: name, kind: lemma-text)
+#let definition(body, name: "") = math-block(body, name: name, kind: definition-text, emphasis: "italics", decoration: "outline")
+#let remark(body, name: "") = math-block(body, name: name, kind: remark-text, decoration: "none")
+#let example(body, name: "") = math-block(body, name: name, kind: example-text, decoration: "none")
 
 // It takes the body of the proof, and formats it by adding the QED
-// symbol at the end, and the _#proof-begin._ text at the front.
-#let proof(body) = [
-  _#proof-begin._ #body #h(3em) #place(right, clearance: 20em, dy: -7pt, qed)
-]
+// symbol at the end, and the _#proof-text._ text at the front.
+#let proof(body) = [_#proof-text._ #body #h(3em) #place(right, dy: -7pt, qed)]
 
 // Configuration of the paper.
 
@@ -152,7 +128,7 @@
 
   if abstract != [] {
     par(justify: false)[
-      #smallcaps[#abstract-begin] \
+      #smallcaps[#abstract-text] \
       #v(0.15em)
       #abstract
       #v(2em)