Texas Instruments TI-89 - Integer_Non_Unknown

472
Appendix A: System Routines — EStack Arithmetic
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
integer_non_unknown
Declaration:
int
integer_non_unknown
(EStackIndex
i
)
Category(ies):
EStack Arithmetic
Description:
Determines if the expression indexed by
i
can have whole-number values.
Inputs:
i
— Index to an algebraic expression.
Outputs:
Returns 1 if the function determines that the expression indexed by
i
can
have only whole-number values. Returns
L
1 if the function determines that
the expression cannot have a whole-number value. Returns 0 if the
function cannot determine either of the above. The argument expression
does not have to be numeric.
Assumptions:
i
indexes the top tag of an algebraic expression.
Side Effects:
None
Availability:
On AMS 2.02 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: is_whole_number, is_Float_exact_whole_number
Examples:
Boolean is_even_expression (EStackIndex i)
/* Returns TRUE if the expression indexed by i is recognized as even. */
{ Access_AMS_Global_Variables;
EStackIndex old_top = top_estack;
Boolean b;
push_reciprocal_of_quantum (2u);
times_top (i);
b = integer_non_unknown (top_estack) > 0;
top_estack = old_top;
return b;
}