** Next:** Using PReMo in practice
** Up:** Input languages
** Previous:** Stochastic Context Free Grammar
** Contents**

Here we define a list of equations separated by a newline character. Each
equation defines a recursive expression that this variable has to fulfill eg.
`x = cos(y) + x` defines an equation for the variable and its
dependence on the variables and . A formal grammar in short could look like this:

I am not going to go in details how expressions in our grammar looks like,
see `http://www.singsurf.org/djep/html/grammar.html` for more details what expressions are allowed. List of supported functions is available here: `http://www.singsurf.org/djep/html/grammar.html`. On top of that we added functions and with arbitrary number of arguments. Obviously if such function occurs in our equation system, Newton method won't work as it won't be able to differentiate them.

Dominik Wojtczak
2006-10-31