Copyright (c) 1992 Association of Mizar Users
environ vocabulary E_SIEC, BOOLE, RELAT_1, S_SIEC; notation TARSKI, XBOOLE_0, ZFMISC_1, STRUCT_0, RELAT_1, E_SIEC; constructors E_SIEC; clusters RELAT_1, ZFMISC_1; theorems SYSREL, E_SIEC; begin definition let N be e_net; redefine func e_Places N; synonym s_transitions N; redefine func e_Transitions N; synonym s_places N; redefine func e_shore N; synonym s_carrier N; redefine func e_entrance N; synonym s_enter N; redefine func e_escape N; synonym s_exit N; redefine func e_adjac N; synonym s_prox N; end; reserve N for e_net; canceled 40; theorem Th41:((the entrance of N) \ diagonal(the carrier of N))~ c= [:e_Places(N),e_Transitions(N):] & ((the escape of N) \ diagonal(the carrier of N))~ c= [:e_Places(N),e_Transitions(N):] proof (the entrance of N) \ diagonal(the carrier of N) c= [:e_Transitions(N),e_Places(N):] & (the escape of N) \ diagonal(the carrier of N) c= [:e_Transitions(N),e_Places(N):] by E_SIEC:24; hence thesis by SYSREL:16; end; definition let N be G_Net; canceled 27; func s_pre(N) -> Relation equals :Def28: ((the escape of N) \ diagonal(the carrier of N))~; coherence; func s_post(N) -> Relation equals :Def29: ((the entrance of N) \ diagonal(the carrier of N))~; coherence; end; canceled; theorem s_post(N) c= [:s_transitions(N),s_places(N):] & s_pre(N) c= [:s_transitions(N),s_places(N):] proof ((the entrance of N) \ diagonal(the carrier of N))~ c= [:s_transitions(N),s_places(N):] & ((the escape of N) \ diagonal(the carrier of N))~ c= [:s_transitions(N),s_places(N):] by Th41; hence thesis by Def28,Def29; end;