let p, q, r be Element of CQC-WFF ; :: thesis: ( p => (q => r) is valid & p => q is valid implies p => r is valid )
assume A1: ( p => (q => r) is valid & p => q is valid ) ; :: thesis: p => r is valid
then (p => q) => (p => r) is valid by Th55;
hence p => r is valid by A1, CQC_THE1:104; :: thesis: verum