let q, s, r, p be Element of CQC-WFF ; :: thesis: (q => s) => (((q => r) => p) => ((s => p) => p)) in TAUT
( ((q => r) => p) => ((q => p) => p) in TAUT & (((q => r) => p) => ((q => p) => p)) => ((q => s) => (((q => r) => p) => ((s => p) => p))) in TAUT ) by Lm4, Lm18;
hence (q => s) => (((q => r) => p) => ((s => p) => p)) in TAUT by CQC_THE1:82; :: thesis: verum