Differentials

Theorem 1. Let σ ,τ be differentials on a cell K such that |σ| and |t | are integrable. Then

(i) (AC2 ) is equivalent to (AC5 ). (ii) (ACa) is equivalent to (ACq).

So for such σ ,τ the conditions (ACi) for i = 2,4 ,5 ,6 are all equivalent.