[ { "non-negative integers" * } {
[ "nat_lt ( ?<? )" "nat_lt_pred" "nat_lt_plus" "nat_lt_minus" "nat_lt_minus_plus" * ]
[ "nat_le ( ?≤? )" "nat_le_pred" "nat_le_plus" "nat_le_minus" "nat_le_minus_plus" * ]
[ { "non-negative integers" * } {
[ "nat_lt ( ?<? )" "nat_lt_pred" "nat_lt_plus" "nat_lt_minus" "nat_lt_minus_plus" * ]
[ "nat_le ( ?≤? )" "nat_le_pred" "nat_le_plus" "nat_le_minus" "nat_le_minus_plus" * ]