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xpress.setConstraintOperatorsEnabled

Purpose
Enables or disables the behaviour where comparing two expressions using the ==, <= or >= operators creates a new constraint.
Synopsis
xpress.setConstraintOperatorsEnabled(enabled)
Argument
enabled 
True if comparing two expressions should create a new constraint, False if comparing two expressions should return a Boolean.
Example
The example below disables constraint operators until a subsequent call to xpress.setConstraintOperatorsEnabled(True): 
xpress.setConstraintOperatorsEnabled(False)
The example below disables constraint operators for the duration of the following code block, and then automatically re-enables them afterwards: 
with xpress.setConstraintOperatorsEnabled(False):
  run_unit_tests()
Further information
1. By default, an expression like x == y, where x and y are xpress.var objects creates a new constraint, fixing x and y to the same value. This is sometimes not the desired behaviour, for example during unit testing, where you might want to determine whether two expressions have the same algebraic form.
2. Whether or not constraint operators are enabled, constraints can always be created using the xpress.constraint constructors (or xpress.eq, xpress.leq and xpress.geq functions), and expressions can always be compared for equality using xpress.is_equal.
Related topics
xpress.getConstraintOperatorsEnabled, xpress.is_equal, xpress.constraint, xpress.eq, xpress.leq, xpress.geq.

Parent Topic Xpress base functions

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