# Intellektik: Technical report 92-14

## Equational Logic Programming, Actions, and Change

### Gerd Große and Steffen Hölldobler and Josef Schneeberger and Ute Sigmund and Michael Thielscher

Recently three approaches for solving planning problems deductively were
proposed each of which does not require to state frame axioms explicitly.
These approaches are based on the linear connection method, an equational
logic programming language, and on linear logic. In this paper, we briefly
review these approaches and show that they are equivalent. Moreover, we
illustrate that these approaches are not only restricted to deductive
planning, but can be applied whenever actions are to be modelled in logic. We
show that the approaches essentially amount on building predicates over the
data structure multiset. Such multisets are interpreted as resources, which are
consumed and produced by actions. We give a minimal and complete unification
algorithm for the equational theory which defines the multisets. Finally, we
discuss possible extensions of the equational logic programming approach.