diff --git a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/AutocompletionCategory.qml b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/AutocompletionCategory.qml
index d5cc9af..cf42238 100644
--- a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/AutocompletionCategory.qml
+++ b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/AutocompletionCategory.qml
@@ -113,9 +113,11 @@ ListView {
         Text {
             id: annotationText
             anchors.right: parent.right
+            anchors.verticalCenter: parent.verticalCenter
             topPadding: 2
             bottomPadding: 2
             rightPadding: 15
+            font.pixelSize: autocompleteText.font.pixelSize - 2
             text: listFiltered.model[index].annotation
             color: parent.selected ? sysPaletteIn.highlightedText : sysPaletteIn.windowText
         }
diff --git a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/ExpressionEditor.qml b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/ExpressionEditor.qml
index 6315e3d..bde4962 100644
--- a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/ExpressionEditor.qml
+++ b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/ExpressionEditor.qml
@@ -448,7 +448,7 @@ Item {
                     itemSelected: parent.itemSelected
                     categoryItems: Parsing.FUNCTIONS_LIST
                     autocompleteGenerator: (item) => {return {
-                        'text': item, 'annotation': '',
+                        'text': item, 'annotation': Parsing.FUNCTIONS_USAGE[item].join(', '),
                         'autocomplete': item+'()', 'cursorFinalOffset': -1
                     }}
                     baseText: parent.visible ? parent.currentToken.value : ""
diff --git a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/common.js b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/common.js
index 86d16e6..450ae6d 100644
--- a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/common.js
+++ b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/common.js
@@ -68,7 +68,7 @@ function parseArgumentsForFunction(args, usage1, usage2) {
             throw EvalError(qsTranslate('usage', 'Usage: %1').arg(usage2))
         f = parser.parse(f).toJSFunction(variable, currentVars)
     } else
-        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2)))
+        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2))
     return f
 }
 
@@ -78,7 +78,7 @@ parser.functions.integral = function(a, b, ...args) {
     let usage2 = qsTranslate('usage', 'integral(<from: number>, <to: number>, <f: string>, <variable: string>)')
     let f = parseArgumentsForFunction(args, usage1, usage2)
     if(a == null || b == null)
-        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2)))
+        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2))
 
     // https://en.wikipedia.org/wiki/Simpson%27s_rule
     // Simpler, faster than tokenizing the expression
@@ -86,12 +86,12 @@ parser.functions.integral = function(a, b, ...args) {
 }
 
 parser.functions.derivative = function(...args) {
-    let usage1 = qsTranslate('usage', 'derivative(<f: ExecutableObject>, <x: variable>)')
-    let usage2 = qsTranslate('usage', 'derivative(<f: string>, <variable: string>, <x: variable>)')
+    let usage1 = qsTranslate('usage', 'derivative(<f: ExecutableObject>, <x: number>)')
+    let usage2 = qsTranslate('usage', 'derivative(<f: string>, <variable: string>, <x: number>)')
     let x = args.pop()
     let f = parseArgumentsForFunction(args, usage1, usage2)
     if(x == null)
-        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2)))
+        throw EvalError(qsTranslate('usage', 'Usage: %1 or\n%2').arg(usage1).arg(usage2))
         
     let derivative_precision = x/10
     return (f(x+derivative_precision/2)-f(x-derivative_precision/2))/derivative_precision
diff --git a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/parsing.js b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/parsing.js
index e1c4019..a7d5d48 100644
--- a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/parsing.js
+++ b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/parsing.js
@@ -29,5 +29,6 @@ var Tokenizer = TK.ExpressionTokenizer
 
 var FUNCTIONS_LIST = Reference.FUNCTIONS_LIST
 var FUNCTIONS = Reference.FUNCTIONS
+var FUNCTIONS_USAGE = Reference.FUNCTIONS_USAGE
 var CONSTANTS_LIST = Reference.CONSTANTS_LIST
 var CONSTANTS = Reference.CONSTANTS
diff --git a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/reference.js b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/reference.js
index 31a5963..36d4111 100644
--- a/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/reference.js
+++ b/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/reference.js
@@ -106,7 +106,7 @@ class P {
     }
     
     toString() {
-        base_string = this.type
+        let base_string = this.type
         if(this.name != '')
             base_string = `${this.name}: ${base_string}`
         if(this.multipleAllowed)
@@ -120,7 +120,7 @@ class P {
 }
 
 let string = new P('string')
-let bool = new P('boolean')
+let bool = new P('bool')
 let number = new P('number')
 let array = new P('array')
 
@@ -153,9 +153,9 @@ const FUNCTIONS_USAGE = {
     'log10': [number],
     'log1p': [number],
     'log2': [number],
-    'max': [number, number, new P('number', '', true, null, true)],
-    'min': [number, number, new P('number', '', true, null, true)],
-    'pow': [number, new P('number', 'exponent')],
+    'max': [number, number, new P('numbers', '', true, true)],
+    'min': [number, number, new P('numbers', '', true, true)],
+    'pow': [number, new P('number', 'exp')],
     'random': [number, number],
     'round': [number],
     'sign': [number],
@@ -170,5 +170,8 @@ const FUNCTIONS_USAGE = {
     'gamma': [number],
     'Γ': [number],
     'roundTo': [number, new P('number')],
+    // Function manipulation
+    'derivative': [new P('f'), new P('string', 'var', true), number],
+    'integral': [new P('from'), new P('to'), new P('f'), new P('string', 'var', true)],
 }