theorem :: JORDAN5B:15

for i being Nat
for f being FinSequence of (TOP-REAL 2)
for P being Subset of (TOP-REAL 2) st f is being_S-Seq & 1 <= i & i + 1 <= len f & P = LSeg (f,i) holds
P is_an_arc_of f /. i,f /. (i + 1)