# ============================================================== 
# Backward rule example
# See https://www.w3.org/2000/10/swap/doc/tutorial-1.pdf page 17
# ============================================================== 

@prefix math: <http://www.w3.org/2000/10/swap/math#>.
@prefix log: <http://www.w3.org/2000/10/swap/log#>.
@prefix : <http://example.org/#>.

# something is more interesting if it is greater
{
 ?X :moreInterestingThan ?Y.
} <= {
 ?X math:greaterThan ?Y.
}.

# derivation (forward)
{
 5 :moreInterestingThan 3.
} => {
 5 :isIndeedMoreInterestingThan 3.
}.