libmatheval1 binary package in Ubuntu Bionic i386

 GNU libmatheval is a library comprising of several procedures that make
 it possible to create an in-memory tree representation of mathematical
 functions over single or multiple variables and later use this
 representation to evaluate functions for specified variable values, to
 create corresponding trees for function derivatives over specified
 variables or to print textual representations of in-memory trees to a
 specified string. The library supports arbitrary variable names in
 expressions, decimal constants, basic unary and binary operators and
 elementary mathematical functions.
 .
 This package contains the runtime shared library.

Source package