ASSOC_CONV : thm -> term -> thm
x op (y op z) = (x op y) op z
# ASSOC_CONV ADD_ASSOC `((1 + 2) + 3) + (4 + 5) + (6 + 7)`;; val it : thm = |- ((1 + 2) + 3) + (4 + 5) + 6 + 7 = 1 + 2 + 3 + 4 + 5 + 6 + 7 # ASSOC_CONV CONJ_ASSOC `((p /\ q) /\ (r /\ s)) /\ t`;; val it : thm = |- ((p /\ q) /\ r /\ s) /\ t <=> p /\ q /\ r /\ s /\ t