This is the preamble to a book I'm editing:

```
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{xspace}
\usepackage{proof}
\usepackage{url}
\usepackage{xy}
\xyoption{all}
\usepackage{amsthm}
\usepackage{stmaryrd}
\usepackage{amsfonts}
\usepackage{amstext}
\usepackage{algorithmic}
\usepackage{algorithm}
\usepackage{graphicx}
\usepackage{epstopdf}
\usepackage{enumerate}
\usepackage{paralist}
\usepackage{mathrsfs}
```

Trying to compile this document yields the error:

```
LaTeX Error: Command \proof already defined.
```

This error only occurred after the inclusion of amsthm in the above list, which I need for one of the chapters. Obviously amsthm is clashing with some other package in the list, but I have no way of finding which one (the other packages are needed for other chapters anyway).

Is there any way of telling LaTeX to ignore the definition of proof from amsthm, thus hopefully resolving the conflict?

**Edit:** The class I'm using is monog3, which is provided to me by Oxford University Press. I don't know if I can share its contents, but I have checked and it does contain the conflicting definition:

```
\def\proof{\trivlist \item[\hskip \labelsep{\bf Proof\ }]}
```

With this in mind, is there a way to get around the clash?

## Best Answer

If the class defines either a macro or an environment called

`proof`

, add the instructions`\let\proof\relax`

and`\let\endproof\relax`

before loading`amsthm`

.