Requirement: Retarded interface I ret

A retarded construction must specify its actual argument domain, normalization convention, admitted coefficients and descendants, old retarded overlaps, and a named continuity statement.

For independently unsmeared source or observation slots, a distributional retarded-support assertion additionally requires a specified multilinear distribution and a proof of its support in the declared causal relation. Vanishing for one functional-support ordering is not that slot-support theorem.

A second retarded order requires higher time ordering and all intermediate products in its defining identity. None is supplied by writing an arity-two subtraction.