Proof Planning with Multiple

Humans have diierent problem solving strategies at their disposal and they can exibly employ several strategies when solving a complex problem, whereas previous planning and theorem proving systems typically employ a single strategy or a hard coded combination of a few strategies. We introduce multi-strategy proof planning that allows to combine a number of strategies and to switch between them in a planning process. Thereby proof planning becomes more robust since it does not necessarily fail if one problem solving mechanism fails. Rather it can reason about preference of strategies and about failures. Moreover, our strategies provide a means for structuring the vast amount of knowledge such that the planner can cope with an otherwise overwhelming knowledge in mathematics. Since diierent strategies can employ diierent algorithms it is possible to combine precondition satisfaction planning with other algorithms that reene or modify a plan. The multi-strategy proof planning is implemented in the system MULTI which has a blackboard architecture.