Texas Instruments TI-89 - Replace_Top2_With_Prod

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Appendix A: System Routines — EStack Arithmetic
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
replace_top2_with_prod
Declaration:
void
replace_top2_with_prod
(EStackIndex
i
)
Category(ies):
EStack Arithmetic
Description:
Replaces the top two expressions of the estack with their
internally-simplified product. If both operands are conforming matrices, it is
the matrix product rather than an element-wise product.
Inputs:
i
— Index to the top tag of the deeper of the top two expressions of the
estack. These top two expressions are internally-simplified
algebraic expressions, algebraic comparisons, or aggregates
thereof.
Outputs:
None
Assumptions:
None
Side Effects:
None
Availability:
On AMS 2.02 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: times_top, push_product, push_negate, negate_top
Example:
Boolean is_odd_expression (EStackIndex i)
/* Returns TRUE if the expression indexed by i is recognized as odd. */
{ Access_AMS_Global_Variables;
EStackIndex old_top;
Boolean b;
if (SIGN_TAG == ESTACK (i))
return IS_DOMAIN_REAL && is_real (i - 1u);
old_top = top_estack;
push_arg_minus_1 (i);
i = top_estack;
push_reciprocal_of_quantum (2u);
replace_top2_with_prod (i);
b = integer_non_unknown (top_estack) > 0;
top_estack = old_top;
return b;
}