def are_not_nat(builder, vals):
 assert (len(vals) >= 1)
 pred = is_not_nat(builder, vals[0])
 for val in vals[1:]:
  pred = builder.and_(pred, is_not_nat(builder, val))
 return pred

def are_not_nat ( builder , vals ) : assert ( len ( vals ) >= 1 ) pred = is_not_nat ( builder , vals [ 0 ] ) for val in vals [ 1 : ] : pred = builder . and_ ( pred , is_not_nat ( builder , val ) ) return pred
return a predicate which is true if all of *vals* are not nat .