Xpress NonLinear Formulae

Xpress NonLinear can handle formulae described in three different ways:

Character strings

The formula is written exactly as it would appear in, for example, the Extended MPS format used for text file input.

Internal unparsed format

The tokens within the formula are replaced by a
{token type, token value} pair. The list of types and values is in the table below.

Internal parsed format

The tokens are converted as in the unparsed format, but the order is changed so that the resulting array forms a reverse-Polish execution stack for direct evaluation by the system.