theorem Th16: :: TOPALG_4:16
for S, T being non empty TopSpace
for s1, s2 being Point of S
for t1, t2 being Point of T st s1,s2 are_connected & t1,t2 are_connected holds
for L1 being Path of s1,s2
for L2 being Path of t1,t2 holds <:L1,L2:> is Path of [s1,t1],[s2,t2]