Riddle (3): What are those, four, four digit, non-zero numbers?

Riddle: 

Two four digit, non zero numbers can nullify one another. There are two pairs of such couples that fit below condition. What are those, four, four digit, non-zero numbers?

Conditions:

Assume, pqrs is the male number and klmn is the female number.

1. In the male number (pqrs), the first number (p) minus the second number (q) is equal to the third number (r) and the second number (q) minus the third number (r) is equal to the fourth number (s).

2. In the female number (klmn), the first number (k) plus the second number (l) is equal to the third number (m) and the second number (l) plus the third number (m) is equal to the fourth number (n).

3. The reverse of the male number (srqp) minus the female number (klmn) is equal to zero.
Date of Writing: 03/07/2015