#846 math edge errors in manual

[snzho]

The manual contains some errors regarding math edges. Solve fails if the arg of log/ln or sqrt goes negative. A divisor going to zero returns 1.0e32 and the run completes. Log/ln of zero returns -1.0e99

--- a/manual.lyx
+++ b/manual.lyx
@@ -25137,10 +25137,7 @@
 \begin_layout Standard
 If the argument of log,
  ln,

- or sqrt becomes less than zero,
- the absolute value of the argument is used.
- If a divisor becomes zero or the argument of log or ln becomes zero,
- an error will result.
+ or sqrt becomes less than zero then the solve will fail.
  Other problems may occur when the argument for a function in a partial derivative enters a region where that function is undefined.
 \end_layout