let p, q be Element of CQC-WFF ; :: thesis: for x being bound_QC-variable st All x,(p => q) is valid holds
(Ex x,p) => (Ex x,q) is valid
let x be bound_QC-variable; :: thesis: ( All x,(p => q) is valid implies (Ex x,p) => (Ex x,q) is valid )
assume A1: All x,(p => q) is valid ; :: thesis: (Ex x,p) => (Ex x,q) is valid
(All x,(p => q)) => ((Ex x,p) => (Ex x,q)) is valid by Th38;
hence (Ex x,p) => (Ex x,q) is valid by A1, CQC_THE1:104; :: thesis: verum