Summary of the Evaluable Predicates


KEY
abolish(F,N)      Abolish the interpreted procedure named F arity N.
abort             Abort execution of the current directive.
arg(N,T,A)        The Nth argument of term T is A.
assert(C)         Assert clause C.
assert(C,R)       Assert clause C, reference R.
asserta(C)        Assert C as first clause.
asserta(C,R)      Assert C as first clause, reference R.
assertz(C)        Assert C as last clause.
assertz(C,R)      Assert C as last clause, reference R.
atom(T)           Term T is an atom.
atomic(T)         Term T is an atom or integer.
bagof(X,P,B)      The bag of instances of X such that P is provable is B.
break             Break at the next interpreted procedure call.
call(P)           Execute the interpreted procedure call P.
clause(P,Q)       There is an interpreted clause, head P, body Q.
clause(P,Q,R)     There is an interpreted clause, head P, body Q, ref R.
close(F)          Close file F.
consult(F)        Extend the interpreted program with clauses from file F.
current_atom(A)   One of the currently defined atoms is A.
current_functor(A,T) A current functor is named A, m.g. term T.
current_predicate(A,P) A current predicate is named A, m.g. goal P.
debug             Switch on debugging.
debugging         Output debugging status information.
dir               List users files (file directory).
display(T)        Display term T on the terminal.
edit(F)           Edit the file F.
edit              Edit the last file edited.
emas(C)           Call the Emas command C.
emas(C,A)         Call the Emas command C with argument A.
erase(R)          Erase the clause or record, reference R.
expand_term(T,X)  Term T is a shorthand which expands to term X.
exists(F)         The file F exists.
fail              Backtrack immediately.
fileerrors        Enable reporting of file errors.
files             List the users files.
functor(T,F,N)    The principal functor of term T has name F, arity N.
get(C)            The next non-blank character input is C.
get0(C)           The next character input is C.
gripe             Mail a complaint/query about the Prolog system.
halt              Halt Prolog, exit to the monitor.
instance(R,T)     A m.g. instance of the record reference R is T.
integer(T)        Term T is an integer.
Y is X            Y is the value of integer expression X.
leash(M)          Set leashing mode to M.
listing           List the current interpreted program.
listing(P)        List the interpreted procedure(s) specified by P.
name(A,L)         The name of atom or integer A is string L.
nl                Output a new line.
nodebug           Switch off debugging.
nofileerrors      Disable reporting of file errors.
nonvar(T)         Term T is a non-variable.
nospy P           Remove spy-points from the procedure(s) specified by P.
not P             Goal P is not provable.
op(P,T,A)         Make atom A an operator of type T precedence P.
print(T)          Portray or else write the term T.
prompt(A,B)       Change the prompt from A to B.
put(C)            The next character output is C.
read(T)           Read term T.
reconsult(F)      Update the interpreted program with procedures from file F.
recorda(K,T,R)    Make term T the first record under key K, reference R.
recorded(K,T,R)   Term T is recorded under key K, reference R.
recordz(K,T,R)    Make term T the last record under key K, reference R.
redo(F)           Edit the file F and then reconsult it.
redo              Redo the last file edited.
rename(F,G)       Rename file F to G.
repeat            Succeed repeatedly.
retract(C)        Erase the first interpreted clause of form C.
save(F)           Save the current state of Prolog in file F.
see(F)            Make file F the current input stream.
seeing(F)         The current input stream is named F.
seen              Close the current input stream.
skip(C)           Skip input characters until after character C.
spy P             Set spy-points on the procedure(s) specified by P.
tab(N)            Output N spaces.
tell(F)           Make file F the current output stream.
telling(F)        The current output stream is named F.
told              Close the current output stream.
trace             Switch on debugging and start tracing immediately.
true              Succeed.
ty(F)             Type the file F on the terminal.
ty                type the last file edited.
var(T)            Term T is a variable.
write(T)          Write the term T.
writeq(T)         Write the term T, quoting names where necessary.
'LC'              The following Prolog text uses lower case.
'NOLC'            The following Prolog text uses upper case only.
 !                Cut any choices taken in the current procedure.
\+ P              Goal P is not provable.
X<Y               As integer values, X is less than Y.
X=<Y              As integer values, X is less than or equal to Y.
X>Y               As integer values, X is greater than Y.
X>=Y              As integer values, X is greater than or equal to Y.
X=Y               Terms X and Y are equal (i.e. unified).
T=..L             The functor and arguments of term T comprise the list L.
X==Y              Terms X and Y are strictly identical.
X\==Y             Terms X and Y are not strictly identical.
[F|R]             Perform the (re)consult(s) specified by [F|R].