for FT being non empty RelStr
for A being Subset of FT
for x1, x2 being Element of FT st ex f being FinSequence of FT st
( f is continuous & rng f c= A & f . 1 = x1 & f . (len f) = x2 ) holds
ex g being FinSequence of FT st g is_minimum_path_in A,x1,x2