| ⊦ cl = [], sources(cl, d) = (((∃ d0. d0 ∈ sources(cl .rest, d) ∧ cdom(cl .first) ⇒ d0) ⊃ sources(cl .rest, d) ++ cdom(cl .first); sources(cl .rest, d))) |
cl = co + cl0 ⊦ cl = [], sources(cl, d) = (((∃ d0. d0 ∈ sources(cl0, d) ∧ cdom(co) ⇒ d0) ⊃ sources(cl0, d) ++ cdom(co); sources(cl0, d)))
[[CONCRETESIMPRULES : ([CSIMPELIM : cl ≠ [] ⊦ co = cl .first ∧ cl0 = cl .rest ↔ cl = co + cl0])], [EXTRATERMS : (cl, co, cl0)]]