can_be_approxed Function (ROM Call 0x2F5)

AMS 1.01 or higher estack.h

short can_be_approxed (CESI ptr, short Complex);

Checks whether an expression can be approximated to a number.

can_be_approxed returns TRUE if the expression pointed to by ptr can be approximated to a number (including transfinite ones) or a list of numbers (such expression are for example 'ln(2+sin(1))/5', '1/0' or 'x^2+1-x*x'), else returns FALSE. Complex is a Boolean parameter: if it is TRUE, complex results will be allowed, but if it is FALSE, complex results will be treated as "can not be approxed".

Note: can_be_approxed performs much detailed investigation than functions likely_approx_to_number and likely_approx_to_complex_number.


Uses: next_expression_index, top_estack, push_approx, primary_tag_list
Used by: push_colnorm, push_rownorm, push_degrees, push_exponentiate