---
layout: stdlib-reference
---

# attribute [PrimalSubstituteOf]

## Description

<span class='code'>[<a href="primalsubstituteof-06g.html">PrimalSubstituteOf</a>(fn)]</span> is the back-reference version of <span class='code'>[<a href="primalsubstitute-06.html">PrimalSubstitute</a>(substFn)]</span>

When used to decorate a function, that function is considered the substitute for the
referenced <span class='code'>fn</span>.
Apart from this difference, the semantics of the substitution are the same as for
<span class='code'>[<a href="primalsubstitute-06.html">PrimalSubstitute</a>(substFn)]</span>


## Signature

<pre>
[<a href="primalsubstituteof-06g.html">PrimalSubstituteOf</a>(<a href="primalsubstituteof-06g.html#decl-function" class="code_param">function</a>)]
</pre>

## Parameters

####  <a id="decl-function"></a>function