let N be with_zero set ; for S being non empty with_non-empty_values IC-Ins-separated Mem-Struct over N
for p, q being PartState of S
for k being Nat st IC in dom q holds
DecIC ((p +* (IncIC (q,k))),k) = p +* q
let S be non empty with_non-empty_values IC-Ins-separated Mem-Struct over N; for p, q being PartState of S
for k being Nat st IC in dom q holds
DecIC ((p +* (IncIC (q,k))),k) = p +* q
let p, q be PartState of S; for k being Nat st IC in dom q holds
DecIC ((p +* (IncIC (q,k))),k) = p +* q
let k be Nat; ( IC in dom q implies DecIC ((p +* (IncIC (q,k))),k) = p +* q )
assume A1:
IC in dom q
; DecIC ((p +* (IncIC (q,k))),k) = p +* q
IC in dom (IncIC (q,k))
by Th52;
hence DecIC ((p +* (IncIC (q,k))),k) =
p +* (DecIC ((IncIC (q,k)),k))
by Th72
.=
p +* q
by A1, Th73
;
verum