let p, q, r be Element of HP-WFF ; :: thesis: (p => (q => r)) => ((p => q) => (p => r)) is pseudo-canonical
reconsider s = (p => (q => r)) => ((p => q) => (p => r)) as canonical Element of HP-WFF by Th42;
s is pseudo-canonical ;
hence (p => (q => r)) => ((p => q) => (p => r)) is pseudo-canonical ; :: thesis: verum