# Matrix-vector representation of a system of linear inequalities

**URL:** https://discourse.julialang.org/t/matrix-vector-representation-of-a-system-of-linear-inequalities/106188
**Category:** General Usage
**Tags:** question, symbolics
**Created:** [November 14, 2023, 8:42am UTC](https://discourse.julialang.org/t/matrix-vector-representation-of-a-system-of-linear-inequalities/106188 "2023-11-14T08:42:31Z")
**Posts on this page:** 1
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### Author: ![jd-foster](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jd-foster/32/35824_2.png) [@jd-foster](https://discourse.julialang.org/u/jd-foster)
#### Post date: [November 14, 2023, 10:25am UTC](https://discourse.julialang.org/t/matrix-vector-representation-of-a-system-of-linear-inequalities/106188/2 "2023-11-14T10:25:34Z")

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There a ways to do this in JuMP, but they’re not documented: e.g.

> [@Get presolved model from Gurobi](https://discourse.julialang.org/t/get-presolved-model-from-gurobi/103827/6):
>
> There is an internal function to create a “standard form” version for inspecting the problem ## JuMP.jl/src/lp\_sensitivity2.jl: # Docstring: # Given a problem: # # r\_l \<= Ax \<= r\_u # c\_l \<= x \<= c\_u # # Return the standard form: # # [A -I] [x, y] = 0 # [c\_l, r\_l] \<= [x, y] \<= [c\_u, r\_u] # If you have an integral problem first do: undo\_relax = relax\_integrality(rmodel); then you can do s = JuMP.\_standard\_form\_matrix(rmodel) julia\> keys(s) (:columns, :lower, :upper, …

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