{"type":"ScholarlyArticle","title":"Backtracking in MLISP2: an efficient backtracking method for LISP","authors":[{"name":"David Canfield Smith","slug":"david-canfield-smith","given":"David Canfield","family":"Smith","affiliation":""},{"name":"Horace J. Enea","slug":"horace-j-enea","given":"Horace J.","family":"Enea","affiliation":""}],"abstract":"An efficient backtracking method for LISP, · used in the MLISP2 language, is described. The method is optimal in the following senses: ( 1) Only necessary state information is saved. The backtracking system routines are sufficiently efficient to require less than ten percent of the execution time of typical jobs . ( 2) Most common operations -- fetching/storing the value of a variable or the property of an atom, function entry/exit -take no longer with backtracking than without it. This is achieved by not changing the way values are stored. (3) If backtracking is not used, an insignificant overhead is involved in maintaining the backtracking capability. The MLISP2 algorithm and philosophy are briefly contrasted w i th those of several existing backtracking systems, with historical comments on the development of the theory of backtracking.","doi":null,"url":"https://ijcai.org/proceedings/1973/84","pdf":"https://ijcai.org/proceedings/1973/0084.pdf","markdown":"https://ijcai.org/proceedings/1973/84.md","bibtex":"https://ijcai.org/proceedings/1973/bibtex/84","volume":{"slug":"1973","title":"Proceedings of the Third International Joint Conference on Artificial Intelligence","short_title":"IJCAI 1973","url":"https://ijcai.org/proceedings/1973/","year":1973,"location":"Stanford, California, USA","dates":"20-23 August 1973","editors":"Nils J. Nilsson","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Hardware and Software for A.I.","track":"Hardware and Software for A.I.","number":84,"pages":{"first":677,"last":684},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}