theorem Th90: :: AOFA_000:90

for A being free preIfWhileAlgebra
for C, I being Element of A
for n being Nat st while (C,I) in (ElementaryInstructions A) |^ n holds
ex i being Nat st
( n = i + 1 & C in (ElementaryInstructions A) |^ i & I in (ElementaryInstructions A) |^ i )