View Code of Problem 6

number = int(input())
rest = {}
# tell_fast = [0 for i in range(number)]
for i in range(number):
    # print("number:", number)
    arry_number = int(input())
    for j in range(arry_number):
        a, b = input().split()
        # if tell_fast[i] == 0:
        #     tell_fast[i] = int(b) - int(a)
        # arry_rest.append(b)
        if int(b)-int(a) == 1:
            rest[i] = 'YES'
        else:
            rest[i] = 'NO'
            # print(arry_number)
        # print("arry_number:", arry_number)
    # rest.append(arry_rest[-1])

# print(rest)
for value in rest.values():
    print(value)