Declare

\usepackage{fp}

both giving a FP-EVAL error message.

Please attach the full source file used, and copy the exact error message.

Thanks to both of you.
Source included.

Error is like:

@Overfull \hbox (16.79755pt too wide) in paragraph at lines 105--105
[] []
( FP-EVAL ( FP-UPN ( FP-RANDOM ( FP-DIV ) ) ( FP-MUL ) ( FP-ADD ) ( FP-TRUNC )
) ) ( FP-EVAL ( FP-UPN ( FP-RANDOM ( FP-DIV ) ) ( FP-MUL ) ( FP-ADD )
( FP-TRUNC ) ) ) ( FP-EVAL ( FP-UPN ( FP-ADD ) ( FP-DIV ) ) )
! Undefined control sequence.
<recently read> \mathbb

l.105 l.105 }@

\pgfmathsetseed{2056} requires

\usepackage{pgf}

\usepackage{fp}

\mathbb requires a mathematical package. By default, I use

\usepackage{amssymb,amsfonts,mathtools}

A tip to find the wrong line : comment \onecopy and the last brace before \end{document}

Thanks, Now it does!

@Gérard: Nice tip!!