Ng_Such_That_Index - Texas Instruments TI-89 Developer's Manual

1208

NG_such_that_index

Declaration: EStackIndex NG_such_that_index
Category(ies): Algebra Utilities
Description: This global variable is the EStackIndex of the currently active "such that"
expression. When a user enters an expression using the "with" ( | )
operator, the expression to the right of the "with" operator is indexed by
NG_such_that_index. In addition, various internal system processes may
supplement or override this expression. The entry point
push_substitute_using_such_that provides a direct way to supplement
or override this expression.
Not applicable.
Inputs:
Outputs: Not applicable.
Assumptions: Access_AMS_Global_Variables must be defined.
Side Effects: Not applicable.
Availability: On AMS 2.04 and higher.
TI-89 / TI-92 Plus
Differences: None
See Also: push_substitute_using_such_that
Example:
The expression x + 1 | x = 3 produces the following external tokenized form
3 1 NONNEGATIVE_INTEGER_TAG X_VAR_TAG EQUATION_TAG X_VAR_TAG 1 1
NONNEGATIVE_INTEGER_TAG ADD_TAG SUCH_THAT_TAG
Then, during the evaluation of the expression x + 1, the expression x = 3 is indexed by
NG_such_that_index at the bolded tag as follows.
3 1 NONNEGATIVE_INTEGER_TAG X_VAR_TAG EQUATION_TAG
The result is that 3 is substituted for x in the expression x + 1 yielding 4 as the result.
TI-89 / TI-92 Plus Developer Guide
Appendix B: Global Variables — Algebra Utilities
Not for Distribution Beta Version January 26, 2001