Whether an assertion may fix a variable to this ground term, i.e. whether it pins a group to it.
A triple term is admitted exactly when it is ground: until its components are known it is a shape, and
that is the business of the pin lattice (datastructures/TermClusterSet!TermClusterSet) instead.
Whether an assertion may fix a variable to this ground term, i.e. whether it pins a group to it.
A triple term is admitted exactly when it is ground: until its components are known it is a shape, and that is the business of the pin lattice (datastructures/TermClusterSet!TermClusterSet) instead.