The acos and asin functions both fail when given a Complex Float argument with the value 1.0. The error message is:

   >> Error detected within library code:
   catdef: division by zero

Presumably the problem is on line 162 of trigcat.spad, which reads:

       asin x == atan(x/sqrt(1-x**2))

Obviously, if x = 1.0, then sqrt(1-x**2) will evaluate to 0.0, resulting in division by zero. The code should probably include an explicit check for this case:

       asin x == if x = 1.0 then pi()/2 else atan(x/sqrt(1-x**2))