let q, r, p, s be Element of CQC-WFF ; :: thesis: ((q => r) => p) => ((q => s) => ((s => p) => p)) in TAUT
( (q => s) => (((q => r) => p) => ((s => p) => p)) in TAUT & ((q => s) => (((q => r) => p) => ((s => p) => p))) => (((q => r) => p) => ((q => s) => ((s => p) => p))) in TAUT ) by Lm19, Th8;
hence ((q => r) => p) => ((q => s) => ((s => p) => p)) in TAUT by CQC_THE1:82; :: thesis: verum