theorem Th95:
  |-_IPC p => (((p '&' q) => FALSUM) => (q => FALSUM))
proof
    q in {q,(p '&' q) => FALSUM,p} by ENUMSET1:def 1; then
A1: {q,(p '&' q) => FALSUM,p} |-_IPC q by Th67;
    (p '&' q) => FALSUM in {q,(p '&' q) => FALSUM,p} by ENUMSET1:def 1; then
A2: {q,(p '&' q) => FALSUM,p} |-_IPC (p '&' q) => FALSUM by Th67;
   p in {q,(p '&' q) => FALSUM,p} by ENUMSET1:def 1; then
A3: {q,(p '&' q) => FALSUM,p} |-_IPC p by Th67;
A04: |-_IPC p => (q => (p '&' q)) by Th22;
   {}(MC-wff) c= {q,(p '&' q) => FALSUM,p}; then
   {q,(p '&' q) => FALSUM,p} |-_IPC p => (q => (p '&' q))
       by A04,Th66; then
   {q,(p '&' q) => FALSUM,p} |-_IPC q => (p '&' q) by A3,Th27; then
   {q,(p '&' q) => FALSUM,p} |-_IPC p '&' q by A1,Th27; then
   {q,(p '&' q) => FALSUM,p} |-_IPC FALSUM by A2,Th27; then
   {(p '&' q) => FALSUM,p} |-_IPC q => FALSUM by Th56; then
   {p} |-_IPC ((p '&' q) => FALSUM) => (q => FALSUM) by Th55;
   hence thesis by Th54;
end;
