This library provides three predicates with associated operators. The operators can be placed in front of goals to debug Prolog programs.
Of these predicates, the most frequently used is
(*)/1, with associated prefix operator
* (star). Placing
* in front of a goal means to generalize away the goal.
* Goal acts as if
Goal did not appear at all in the source code. It is declaratively equivalent to commenting out the goal, and easier to write, because
* can also be placed in front of the last goal in a clause without any additional changes.
Generalize away Goal.
Provide a trace for calls of Goal.
Portray exceptions thrown by Goal.