% Examples of complicated substitutions in condensed detachment. % These occur in Larry Wos's proofs that XCB is a single axiom for EC. set(hyper_res). assign(max_given, 1). list(usable). % Condensed detachment, but we'll also show the instance of the minor premise. -major(e(x,y)) | -minor(x) | P(y) | minor_instance(x). % condensed detachment major(e(e(e(e(e(x,e(y,e(e(e(e(e(z,e(e(e(z,u),e(v,u)),v)),e(e(w,e(e(e(w, v6),e(v7,v6)),v7)),y)),v8),e(v9,v8)),v9))),x),v10),e(v11,v10)),v11)). end_of_list. list(sos). minor(e(e(e(e(e(e(x,e(e(y,e(e(e(y,z),e(u,z)),u)),x)),e(v,e(e(e(v,w), e(v6,w)),v6))),v7),v8),e(v7,v8)),e(v9,e(e(e(v9,v10),e(v11,v10)),v11)))). end_of_list. % The preceding example has a minor instance with almost 3,000 symbols; % the conclusion is P(e(e(e(x,e(y,e(e(e(y,z),e(u,z)),u))),v),e(x,v))). % % The following example has a minor instance with almost 10,000 symbols. % % major(e(e(e(e(e(e(e(e(x,e(e(e(x,y),e(z,y)),z)),u),v),e(u,v)),e(e(w,e(e(v6, % e(e(e(v6,v7),e(v8,v7)),v8)),e(e(v9,e(e(e(v9,v10),e(v11,v10 )),v11)), % w))),e(v12,e(e(e(v12,v13),e(v14,v13)),v14)))),v15),e(v16,v15)),v16)) % % minor(e(e(e(e(e(x,e(e(e(x,y),e(z,y)),z)),u),v),e(u,v)),e(w, % e(e(e(e(e(e(e(e(e(e(e(v6,e(e(e(v6,v7),e(v8,v7)),v8)),v9),v10),e(v9, % v10)),v11),e(v12,v11)),v12),w),v13),e(v14,v13)),v14)))). % % The conclusion is P(e(e(e(e(e(e(x,e(e(e(x,y),e(z,y)),z)),u),v),e(u,v)), % e(e(e(w,v6),e(v7,v6)),v7)),w)).