let O be non empty connected Poset; for T being non empty array of O
for p, q, s being Element of dom T st p in s & s in q holds
( ((T,p,q) incl) . (p,s) = [p,s] & ((T,p,q) incl) . (s,q) = [s,q] )
let T be non empty array of O; for p, q, s being Element of dom T st p in s & s in q holds
( ((T,p,q) incl) . (p,s) = [p,s] & ((T,p,q) incl) . (s,q) = [s,q] )
let p, q, s be Element of dom T; ( p in s & s in q implies ( ((T,p,q) incl) . (p,s) = [p,s] & ((T,p,q) incl) . (s,q) = [s,q] ) )
assume
( p in s & s in q )
; ( ((T,p,q) incl) . (p,s) = [p,s] & ((T,p,q) incl) . (s,q) = [s,q] )
then
( p c= s & s c= q )
by ORDINAL1:def 2;
hence
( ((T,p,q) incl) . (p,s) = [p,s] & ((T,p,q) incl) . (s,q) = [s,q] )
by Th62; verum