Basic Relfun commands
~~~~~~~~~~~~~~~~~~~~~

The basic Relfun commands you may need are as follows:

Remember:
The arrow keys can be used (e.g., to go up to an earlier input line).
Copy  = Highlight + Enter
Paste = Right Mouse Button

Example:
rfi-p> az lensha([],0).
rfi-p> az lensha([X|Z],N) :- lensha(Z,M), presuc(M,N).
rfi-p> az presuc(0,1).
rfi-p> az presuc(1,2).
rfi-p> az presuc(2,3).
Defines lensha, clause by clause, asserting each clause to the
end ("az") of the current database.

rfi-p> rx presuc(2,3).
Removes one clause, exactly as specified after the "rx". 

rfi-p> tell lensha
Writes contents of the current database to file "lensha.rfp",
in the directory/folder from which Relfun is started. E.g.:
lensha([],0).
lensha([X|Z],N) :- lensha(Z,M), presuc(M,N).
presuc(0,1).
presuc(1,2).

It is better to prepare/edit ".rfp" files outside the interpreter,
e.g. in the directory/folder from which Relfun is started, and always
read in clauses from there (or give a corresponding pathname). E.g.:
lensha([],0).
lensha([X|Z],N) :- lensha(Z,M), presuc(M,N).
presuc(N,suc[N]).

rfi-p> consult lensha
Reads file "lensha.rfp", adding its clauses to the end of the database.
(Beware of duplicate clauses!)

rfi-p> replace lensha
Reads file "lensha.rfp", replacing all existing clauses of the database.

(So
rfi-p> replace lensha
is equivalent to
rfi-p> destroy
rfi-p> consult lensha
)

rfi-p> l
or
rfi-p> listing
Shows the current database.

rfi-p> m
or
rfi-p> more
Computes more (non-deterministic) solutions.

rfi-p> trace lensha
Changes the database such that lensha will be traced.

rfi-p> untrace lensha
Changes the database such that lensha will not be traced.

rfi-p> untrace
Changes the database such that no operation will be traced.

rfi-p> spy
Switches to spy mode to show left-to-right processing of conjunctions.

rfi-p> nospy
Switches to normal mode.