Functions on equation

Function: void translate_equations (equation_t* eqn, size_t size, int offset)

Add offset to the field .var of equations belonging to the array eqn of size size. offset may be negative or positive.

Function: int cmp_equations (const equation_t* eqna, const equation_t* eqnb)

Compare the field .var of the two equations.

Function: int sort_equations (equation_t* eqn, size_t size)

Sort the array eqn of size size according to the field var in ascending order.