Texas Instruments TI-89 Developer's Guide

Appendix A: System Routines — EStack Utilities
521
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
deleted_expression
Declaration:
EStackDisplacement
deleted_expression
(EStackIndex
i
)
Category(ies):
EStack Utilities
Description:
Deletes the estack expression indexed by
i
. Global
top_estack
is reduced
by the number of deleted quantums. Returns the number of deleted
quantums.
Inputs:
i
— Index of the top (highest address) tag of an estack expression.
Outputs:
Number of deleted quantums.
Assumptions:
None
Side Effects: top_estack
is reduced by the number of deleted quantums.
Availability:
On AMS 1.05 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: deleted_between, delete_between, delete_expression,
move_between_to_top, moved_between_to_top
Example:
EStackIndex push_cofactors (EStackIndex i, EStackIndex j)
/* i and j index internally-simplified algebraic expressions.
Let gcd denote their greatest common divisor.
Pushes onto the estack (expression j)/gcd then (expression i)/gcd,
then returns the index of the deeper pushed cofactor.
*/
{ i = push_gcd_then_cofactors (i, j, &j);
return j – deleted_expression (i);
}

Texas Instruments TI-89 Specifications

General

Display size (HxV)	100 x 160 mm
Memory type	639K FLASH ROM, 188K bytes RAM
Compatible operating systems	Operating System 2.09
Battery type	AAA