for r, s being Real
for V being RealLinearSpace
for v being VECTOR of V
for L1, L2 being Linear_Combination of V
for p being Real st ((r * L1) + ((1 - r) * L2)) . v <= p & p <= ((s * L1) + ((1 - s) * L2)) . v holds
ex rs being Real st
( ((rs * L1) + ((1 - rs) * L2)) . v = p & ( r <= s implies ( r <= rs & rs <= s ) ) & ( s <= r implies ( s <= rs & rs <= r ) ) )