diff --git a/notes.txt b/notes.txt
index 5c1fef7..bdd63c0 100644
--- a/notes.txt
+++ b/notes.txt
@@ -33,6 +33,7 @@ go through the tests for docs
 test all docs
 warn nows usage in docs, e.g. spaces in symbol = [a-z]+
 test error report on invalid flag
+report unused definitions
 
 [optimization]
 try preallocate larger store chunks
diff --git a/sequence.go b/sequence.go
index 5e7e633..98c22b4 100644
--- a/sequence.go
+++ b/sequence.go
@@ -181,119 +181,7 @@ func (d *sequenceDefinition) parser() parser {
 	return d.sparser
 }
 
-func (d *sequenceDefinition) builder() builder { return d.sbuilder }
-
-func (d *sequenceDefinition) isCharSequence(r *registry) bool {
-	for i := range d.originalItems {
-		item := normalizeItemRange(d.originalItems[i])
-		if item.Min != 1 || item.Max != 1 {
-			return false
-		}
-
-		itemDef, _ := r.definition(d.originalItems[i].Name)
-		c, ok := itemDef.(*charParser)
-		if !ok || !c.isSingleChar() {
-			return false
-		}
-	}
-
-	return true
-}
-
-func (d *sequenceDefinition) format(r *registry, f formatFlags) string {
-	if d.isCharSequence(r) {
-		if len(d.originalItems) == 1 {
-			itemDef, _ := r.definition(d.originalItems[0].Name)
-			c, _ := itemDef.(*charParser)
-			return c.format(r, f)
-		}
-
-		var chars []rune
-		for i := range d.originalItems {
-			itemDef, _ := r.definition(d.originalItems[i].Name)
-			c, _ := itemDef.(*charParser)
-			chars = append(chars, c.chars[0])
-		}
-
-		chars = escape(charClassEscape, []rune(charClassBanned), chars)
-		return string(append([]rune{'"'}, append(chars, '"')...))
-	}
-
-	var chars []rune
-	for i := range d.originalItems {
-		if len(chars) > 0 {
-			chars = append(chars, ' ')
-		}
-
-		item := normalizeItemRange(d.originalItems[i])
-		needsQuantifier := item.Min != 1 || item.Max != 1
-
-		itemDef, _ := r.definition(item.Name)
-		isSymbol := itemDef.commitType()&userDefined != 0
-
-		ch, isChoice := itemDef.(*choiceDefinition)
-		isChoiceOfMultiple := isChoice && len(ch.options) > 1
-
-		seq, isSequence := itemDef.(*sequenceDefinition)
-		isSequenceOfMultiple := isSequence && len(seq.originalItems) > 1 && !seq.isCharSequence(r)
-
-		needsGrouping := isChoiceOfMultiple || isSequenceOfMultiple
-
-		if isSymbol {
-			chars = append(chars, []rune(itemDef.nodeName())...)
-		} else {
-			if needsGrouping {
-				chars = append(chars, '(')
-			}
-
-			chars = append(chars, []rune(itemDef.format(r, f))...)
-
-			if needsGrouping {
-				chars = append(chars, ')')
-			}
-		}
-
-		if !needsQuantifier {
-			continue
-		}
-
-		if item.Min == 0 && item.Max == 1 {
-			chars = append(chars, '?')
-			continue
-		}
-
-		if item.Min == 0 && item.Max < 0 {
-			chars = append(chars, '*')
-			continue
-		}
-
-		if item.Min == 1 && item.Max < 0 {
-			chars = append(chars, '+')
-			continue
-		}
-
-		chars = append(chars, '{')
-
-		if item.Min == item.Max {
-			chars = append(chars, []rune(strconv.Itoa(item.Min))...)
-		} else {
-			if item.Min > 0 {
-				chars = append(chars, []rune(strconv.Itoa(item.Min))...)
-			}
-
-			chars = append(chars, ',')
-
-			if item.Max >= 0 {
-				chars = append(chars, []rune(strconv.Itoa(item.Max))...)
-			}
-		}
-
-		chars = append(chars, '}')
-	}
-
-	return string(chars)
-}
-
+func (d *sequenceDefinition) builder() builder   { return d.sbuilder }
 func (p *sequenceParser) nodeName() string       { return p.name }
 func (p *sequenceParser) nodeID() int            { return p.id }
 func (p *sequenceParser) commitType() CommitType { return p.commit }
@@ -456,3 +344,114 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 		tokens: c.tokens,
 	}}, true
 }
+
+func (d *sequenceDefinition) isCharSequence(r *registry) bool {
+	for i := range d.originalItems {
+		item := normalizeItemRange(d.originalItems[i])
+		if item.Min != 1 || item.Max != 1 {
+			return false
+		}
+
+		itemDef, _ := r.definition(d.originalItems[i].Name)
+		c, ok := itemDef.(*charParser)
+		if !ok || !c.isSingleChar() {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (d *sequenceDefinition) format(r *registry, f formatFlags) string {
+	if d.isCharSequence(r) {
+		if len(d.originalItems) == 1 {
+			itemDef, _ := r.definition(d.originalItems[0].Name)
+			c, _ := itemDef.(*charParser)
+			return c.format(r, f)
+		}
+
+		var chars []rune
+		for i := range d.originalItems {
+			itemDef, _ := r.definition(d.originalItems[i].Name)
+			c, _ := itemDef.(*charParser)
+			chars = append(chars, c.chars[0])
+		}
+
+		chars = escape(charClassEscape, []rune(charClassBanned), chars)
+		return string(append([]rune{'"'}, append(chars, '"')...))
+	}
+
+	var chars []rune
+	for i := range d.originalItems {
+		if len(chars) > 0 {
+			chars = append(chars, ' ')
+		}
+
+		item := normalizeItemRange(d.originalItems[i])
+		needsQuantifier := item.Min != 1 || item.Max != 1
+
+		itemDef, _ := r.definition(item.Name)
+		isSymbol := itemDef.commitType()&userDefined != 0
+
+		ch, isChoice := itemDef.(*choiceDefinition)
+		isChoiceOfMultiple := isChoice && len(ch.options) > 1
+
+		seq, isSequence := itemDef.(*sequenceDefinition)
+		isSequenceOfMultiple := isSequence && len(seq.originalItems) > 1 && !seq.isCharSequence(r)
+
+		needsGrouping := isChoiceOfMultiple || isSequenceOfMultiple
+
+		if isSymbol {
+			chars = append(chars, []rune(itemDef.nodeName())...)
+		} else {
+			if needsGrouping {
+				chars = append(chars, '(')
+			}
+
+			chars = append(chars, []rune(itemDef.format(r, f))...)
+
+			if needsGrouping {
+				chars = append(chars, ')')
+			}
+		}
+
+		if !needsQuantifier {
+			continue
+		}
+
+		if item.Min == 0 && item.Max == 1 {
+			chars = append(chars, '?')
+			continue
+		}
+
+		if item.Min == 0 && item.Max < 0 {
+			chars = append(chars, '*')
+			continue
+		}
+
+		if item.Min == 1 && item.Max < 0 {
+			chars = append(chars, '+')
+			continue
+		}
+
+		chars = append(chars, '{')
+
+		if item.Min == item.Max {
+			chars = append(chars, []rune(strconv.Itoa(item.Min))...)
+		} else {
+			if item.Min > 0 {
+				chars = append(chars, []rune(strconv.Itoa(item.Min))...)
+			}
+
+			chars = append(chars, ',')
+
+			if item.Max >= 0 {
+				chars = append(chars, []rune(strconv.Itoa(item.Max))...)
+			}
+		}
+
+		chars = append(chars, '}')
+	}
+
+	return string(chars)
+}