Control

,

conjunction, and

;

disjunction, or

->

implication, if-then-else together with disjunction

!

cut, remove choices

call/1

call argument as a predicate call

once/1

call argument as a predicate call, find one solution only

not/1

negation, fail if call to argument succeeds

true/0

always succeed, empty predicate definition

block/3

define a block in order to catch exceptions

exit_block/1

jump out of a block

Do Loops

do

general iteration operator

foreach

iterate over each element in a list

foreacharg

iterate over each argument of a term

fromto

accumulator argument

for

iterate over all integers between two bounds

param

declare parameter variables which are passed into the do-loop