# How can I prevent AMPL from transforming my problem?

**URL:** <https://discuss.ampl.com/t/how-can-i-prevent-ampl-from-transforming-my-problem/71>\
**Category:** FAQs\
**Tags:** files-preprocessing\
**Created:** [December 15, 2021, 5:57pm UTC](https://discuss.ampl.com/t/how-can-i-prevent-ampl-from-transforming-my-problem/71 "2021-12-15T17:57:46Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![megrobert](https://avatars.discourse-cdn.com/v4/letter/m/d07c76/32.png) [@megrobert](https://discuss.ampl.com/u/megrobert)\
**Post date:** [December 15, 2021, 5:57pm UTC](https://discuss.ampl.com/t/how-can-i-prevent-ampl-from-transforming-my-problem/71/1 "2021-12-15T17:57:46Z")

</div>

To suppress the presolve phase, set `option presolve 0` .

To suppress transformation of piecewise-linear terms, set `option pl_linearize 0` .

To suppress elimination of variables by substitution from constraints, set `option substout 0` . (This is the default setting.) Substitutions specified within `var` declarations are always applied.

To see a summary of transformations performed, set `option show_stats 1` .