An extension of Common Lisp providing nondeterministic backtracking and constraint programming. . [Isn' t all backtracking nondeterministic by definition?]

In addition suitable contents:
[ = ] [ ai ] [ al ] [ am ] [ an ] [ ar ] [ arc ] [ b ] [ ba ] [ backtracking ] [ by ] [ C ] [ ch ] [ ck ] [ co ] [ Common Lisp ] [ con ] [ cons ] [ constraint ] [ cr ] [ de ] [ deterministic ] [ ding ] [ du ] [ ed ] [ edu ] [ er ] [ et ] [ extension ] [ fi ] [ file ] [ gr ] [ h ] [ hr ] [ id ] [ il ] [ in ] [ int ] [ io ] [ is ] [ it ] [ ki ] [ Lex ] [ Lisp ] [ mm ] [ mo ] [ mod ] [ module ] [ na ] [ ng ] [ ni ] [ no ] [ nondeterministic ] [ ns ] [ om ] [ ph ] [ pr ] [ program ] [ programming ] [ query ] [ rc ] [ re ] [ ro ] [ sc ] [ se ] [ si ] [ sn ] [ st ] [ tar ] [ tp ] [ tr ] [ track ] [ tracking ] [ vi ] [ Z ]