theorem Th7: :: MODELC_3:7

for L being FinSequence
for F, H being LTL-formula
for W, W1 being Subset of (Subformulae H) st rng L = Subformulae H & L is one-to-one & not F in W & W1 = W \/ {F} holds
len (L,W1) = (len (L,W)) + (len F)