:: deftheorem Def30 defines bool-correct AOFA_A00:def 30 :
for B being BoolSignature holds
( B is bool-correct iff ( len the connectives of B >= 3 & the connectives of B . 1 is_of_type {} , the bool-sort of B & the connectives of B . 2 is_of_type <* the bool-sort of B*>, the bool-sort of B & the connectives of B . 3 is_of_type <* the bool-sort of B, the bool-sort of B*>, the bool-sort of B ) );