diff --git a/src_main/math/pievaluator.cpp b/src_main/math/pievaluator.cpp
index 1209a609..72a47c24 100755
--- a/src_main/math/pievaluator.cpp
+++ b/src_main/math/pievaluator.cpp
@@ -70,8 +70,8 @@
  * * ctg(x) - cotangent
  * * arcsin(x) - arcsine
  * * arccos(x) - arccosine
- * * arctg(x) -arccotangent
- * * arcctg(x) - arctangent
+ * * arctg(x) - arctangent
+ * * arcctg(x) - arccotangent
  * * sh(x) - hyperbolical sine
  * * ch(x) - hyperbolical cosine
  * * th(x) - hyperbolical tangent