let A be QC-alphabet ; :: thesis: for p, q, r being Element of CQC-WFF A holds ((p => r) '&' (q => r)) => ((p 'or' q) => r) in TAUT A
let p, q, r be Element of CQC-WFF A; :: thesis: ((p => r) '&' (q => r)) => ((p 'or' q) => r) in TAUT A
set P = p => r;
set Q = q => r;
set R = (p 'or' q) => r;
( (p => r) => ((q => r) => ((p 'or' q) => r)) in TAUT A & ((p => r) => ((q => r) => ((p 'or' q) => r))) => (((p => r) '&' (q => r)) => ((p 'or' q) => r)) in TAUT A ) by Th32, Th35;
hence ((p => r) '&' (q => r)) => ((p 'or' q) => r) in TAUT A by CQC_THE1:46; :: thesis: verum