let p, q be Element of CQC-WFF ; :: thesis: for X being Subset of CQC-WFF st X |- p holds
X |- q => p
let X be Subset of CQC-WFF ; :: thesis: ( X |- p implies X |- q => p )
assume A1: X |- p ; :: thesis: X |- q => p
X |- p => (q => p) by Th45, CQC_THE1:98;
hence X |- q => p by A1, CQC_THE1:92; :: thesis: verum