--- a/ArithmeticValue.st	Fri Sep 22 10:29:37 2017 +0200
+++ b/ArithmeticValue.st	Fri Sep 22 10:31:47 2017 +0200
@@ -92,26 +92,46 @@
 !
 
 domainErrorSignal
-    "return the signal which is raised on math errors
-     (such as log of 0 etc.)"
+    "return the signal which is raised on some math errors,
+     when the argument is outside the legal domain.
+     (such as arcSin of 2 etc.)"
 
     ^ DomainError
+
+    "
+     2 arcSin
+     0 log     - raises infiniteResult, which is a child of DomainError
+    "
+
+    "Modified (comment): / 22-09-2017 / 09:50:41 / cg"
 !
 
 imaginaryResultSignal
     "return the signal which is raised when an imaginary result would be created
-     (such as when taking the sqrt of a negative number)"
+     (such as when taking the sqrt of a negative number).
+     This error can be handled by wrapping the computation inside a trapImaginary
+     block; then, a complex result is generated."
 
     ^ ImaginaryResultError
+
+    "
+     -2 sqrt
+     
+     Complex trapImaginary:[ -2 sqrt ]
+    "
+
+    "Modified (comment): / 22-09-2017 / 09:53:58 / cg"
 !
 
 infiniteResultSignal
-    "return the signal which is raised when an infinite result would be created
+    "return the signal which is raised when an infinite result would be created.
+     This is a subclass of DomainError.
      (such as when taking the logarithm of zero)"
 
     ^ InfiniteResultError
 
     "Created: / 03-07-2017 / 15:46:02 / cg"
+    "Modified (comment): / 22-09-2017 / 09:49:15 / cg"
 !
 
 operationNotPossibleSignal
@@ -119,9 +139,18 @@
 !
 
 overflowSignal
-    "return the signal which is raised on overflow conditions (in floats)"
+    "return the signal which is raised on overflow conditions (in floats).
+     Attention: currently not raised on all architectures; some return NaN"
 
     ^ OverflowError
+
+    "
+     10e300 * 10e30
+     
+     10q300 * 10e30
+    "
+
+    "Modified (comment): / 22-09-2017 / 09:58:49 / cg"
 !
 
 rangeErrorSignal
@@ -135,9 +164,16 @@
 !
 
 underflowSignal
-    "return the signal which is raised on underflow conditions (in floats)"
+    "return the signal which is raised on underflow conditions (in floats)
+     Attention: currently not raised on all architectures; some return zero"
 
     ^ UnderflowError
+
+    "
+     10e-300 / 10e30
+    "
+
+    "Modified (comment): / 22-09-2017 / 09:58:57 / cg"
 !
 
 unorderedSignal
@@ -145,6 +181,13 @@
      for which no ordering is defined (for example: complex numbers)"
 
     ^ UnorderedNumbersError
+
+    "
+     (0 + 3i) > (0 + 4i)
+     3i > 4i
+    "
+
+    "Modified (comment): / 22-09-2017 / 09:57:28 / cg"
 ! !
 
 !ArithmeticValue class methodsFor:'class initialization'!
@@ -265,7 +308,7 @@
 
 trapImaginary:aBlock
     "evaluate aBlock; 
-     if any DomainError occurs inside, which would return an imaginary result, 
+     if any ImaginaryResult occurs inside, which would return an imaginary result, 
      (eg. square root of negative number),
      convert the result to a complex number and proceed.
      
@@ -278,6 +321,7 @@
             msgSend := ex parameter.
             selector := msgSend selector.
             rcvr := msgSend receiver.
+            
             (selector == #sqrt or: [selector == #sqrtTruncated]) ifTrue: [
                 (rcvr isNumber and:[rcvr isReal]) ifTrue:[
                     ex proceedWith:(rcvr abs perform:selector) i
@@ -292,8 +336,13 @@
                     ] ifFalse:[
                         ex proceedWith:(rcvr abs asComplex sqrt floor) i
                     ].    
+                ] ifFalse: [
+                    (selector == #nthRoot:) ifTrue: [
+                        ex proceedWith:(rcvr abs nthRoot:msgSend argument) i
+                    ]
                 ]
             ].
+
             ex reject
         ] do: 
             aBlock
@@ -324,7 +373,7 @@
          ]
     "
 
-    "Modified: / 03-07-2017 / 15:53:49 / cg"
+    "Modified: / 22-09-2017 / 10:18:14 / cg"
 !
 
 trapInfinity:aBlock
@@ -1685,6 +1734,7 @@
     ^ self * self
 ! !
 
+
 !ArithmeticValue methodsFor:'queries'!
 
 respondsToArithmetic