Logtk.RewriteSourceRewriting is a (relatively) efficient way of computing on terms and literals using rules that come from the input. Each rule is a pair lhs, rhs (left-hand side, right-hand side) that means that objects matching lhs should be rewritten into rhs.
For term rules, lhs and rhs are both terms (with vars rhs ⊆ vars lhs).
For literal rules, lhs is an atomic literal, and rhs is a list of clauses.
This is used for Deduction Modulo in the prover.
Payload of a defined function symbol or type
A constant that is defined by at least one rewrite rule