Bug in p.add_constraint (when input is True/False)

[nathanncohen]

That awful thing again. See bug report at :
https://groups.google.com/d/topic/sage-support/VVTWhE0w7i0/discussion

The problem is that the linear functions need to integrate with the rest of sage to play nice. The patched mip.pyx adds a parent class for linear functions and suitable coercion and rich comparison. Now the following works as expected:

sage: p = MixedIntegerLinearProgram()
sage: x = p.new_variable()
sage: x[1] >= 10
10 <= x_0
sage: 10 <= x[1]
10 <= x_0

Apply attachment: trac_13646_fix_mip.patch

CC: @vbraun @ypfmde @dimpase @ptrrsn

Component: linear programming

Author: Nathann Cohen, Volker Braun

Reviewer: Dmitrii Pasechnik

Merged: sage-5.5.beta1

Issue created by migration from https://trac.sagemath.org/ticket/13646

[nathanncohen]

comment:3

Here it is ! There was some bad side effect with the previous patch :-)

Nathann

[nathanncohen]

comment:4

RHAAAAAAAAAAAAAAAAA

[vbraun]

comment:5

Don't just raise the error on some hand-picked "wrong" values. Add an else: branch to the last if-statement in __init__ as a catch-all.