for XSB prolog,regarding error

Question

whatever simple code , I am running in Xsb prolog using Eclipse IDE , It is showing me error like this:

++Error[XSB/Runtime/P]: [Existence (No procedure usermod : demo / 1 exists)] []

Forward Continuation...

... machine:xsb_backtrace/1

... loader:load_pred1/1

... loader:load_pred0/1

... loader:load_pred/1

... x_interp:_$call/1

... x_interp:call_query/1

... standard:call_expose/1

... standard:catch/3

... x_interp:interpreter/0

... loader:ll_code_call/3

... standard:call_expose/1

... standard:catch/3

give me solution ,if any one is aware of this.

Answer 1

This error means that you are trying to call demo/1 predicate but it is not known to the system. So maybe demo/1 is not defined, or you forgot to consult your source file after defining it.