| d0 ∈ sources(co ', d), d1 ∈ sources(co ', d0) ⊦ sources(co ', d) = ∅, sources(co ', d0) = ∅, # sources(co ', d) = 0, # sources(co ', d0) = 0, d1 ∈ sources(co ', d) |
⊦ sources(co ', d) = (((∃ d0. d0 ∈ sources([], d) ∧ cdom(co) ⇒ d0) ⊃ sources([], d) ++ cdom(co); sources([], d)))
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (d, co)]]