Implementational Issues in GCLA: A-Sufficiency and the Definiens Operation

Aronsson, Martin (1993) Implementational Issues in GCLA: A-Sufficiency and the Definiens Operation. [SICS Report]



We present algorithms for computing A-sufficient substitutions and constraint sets together with the definiens operation. These operations are primitive operations in the language GCLA. The paper first defines those primitives, which together form a dual rule to SLD resolution, and then describes the different algorithms and some of their properties together with examples. One of the algorithms shows how a definition can be compiled into a representation holding all possible A-sufficient substitutions/constraint sets together with their corresponding definiens. This representation makes the computation at runtime of a definiens and an A-sufficient substitution/constraint set have the same complexity as the table lookup operation clause/2 in Prolog. The paper also describes the generalisation from unification (sets of equalities) to constraint sets and satisfiability of systems of equalities and inequalities.

Item Type:SICS Report
Uncontrolled Keywords:GCLA, inequality, constraints, negation
ID Code:2119
Deposited By:Vicki Carleson
Deposited On:22 Oct 2007
Last Modified:18 Nov 2009 16:00

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