Backward Chaining Goal

Summary

Find the next meta-interpreter rule instantiation that will fire.

Signature

instantiation variable

Arguments

variable

An unbound variable introduced by ? .

Description

This backward chaining goal is only relevant when writing a meta-interpreter for a context. It binds variable to the next preferred instantiation from the conflict set of the currently executing context.

This goal may be satisfied repeatedly each time returning the next instantiation. When no instantiations are left, it fails.

Examples

(instantiation ?instantiation)

See also

conflict-set
inst-bindings
inst-rulename
inst-token
start-cycle
fire-rule
defcontext
standard-context