It was in the following summer of 1972, that Kowalski, again working with Colmerauer, developed the procedural interpretation of implications in clausal form. It also became clear that such clauses could be restricted to definite clauses or Horn clauses, and that SL-resolution could be restricted (and generalised) to SLD resolution. Kowalski's procedural interpretation and SLD were described in a 1973 memo, published in 1974. Also in Proceedings IFIP Congress, Stockholm, North Holland Publishing Co., 1974, pp. 569–574.
I,t was in the following summer of 1972, that Kowalski, again working with Colmerauer, developed the procedural interpretation of implications in clausal form. It also became clear that such clauses could be restricted to definite clauses or Horn clauses, and that SL-resolution could be restricted (and generalised) to SLD resolution. Kowalski's procedural interpretation and SLD were described in a 1973 memo published in 1974. Also in Proceedings IFIP Congress, Stockholm, North Holland Publishing Co., 1974, pp. 569–574.