# Symbolics, evaluate expression, but not all the way?

**URL:** <https://discourse.julialang.org/t/symbolics-evaluate-expression-but-not-all-the-way/126736>\
**Category:** General Usage\
**Tags:** question, symbolics\
**Created:** [March 9, 2025, 8:58pm UTC](https://discourse.julialang.org/t/symbolics-evaluate-expression-but-not-all-the-way/126736 "2025-03-09T20:58:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Veenty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/veenty/32/50940_2.png) [@Veenty](https://discourse.julialang.org/u/Veenty)\
**Post date:** [March 9, 2025, 8:58pm UTC](https://discourse.julialang.org/t/symbolics-evaluate-expression-but-not-all-the-way/126736/1 "2025-03-09T20:58:25Z")

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I have an expression of the form

```julia
using Symbolics
@variables x
V1 = cosh(x+1) + sinh(x + 1)
V2 = sinh(x - 1)

```

Somehow I would like to evaluate this expressions at 0, but I would like for it too look like

```julia
V1 = cosh(1) + sinh(1)
V2 = -sinh(1)

```

What would be even better would be to introduce new variables, so that cosh(1) = var1 and sinh(1)=var2

I have too many of this expressions and doing it manually sounds like a pain.

Any idea on how to do this?

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [March 10, 2025, 12:11am UTC](https://discourse.julialang.org/t/symbolics-evaluate-expression-but-not-all-the-way/126736/2 "2025-03-10T00:11:07Z")

</div>

You could try to basically do `substitute` but change the walk so it’s not recursive.