: Test for source tree numbering (A): Level A (A--1): Level B (A--2): Level B (A--2--1): Level C (A--3): Level B (A--3--1): Level C (A--3--1--1): Level D (B): Level A (B--1): Level B (B--1--1): Level C (B--1--1--1): Level D (B--1--1--1--1): Level E (C): Level A (C--1): Level B (C--1--1): Level C (C--1--1--1): Level D (C--1--1--1--1): Level E (C--1--1--2): Level D (C--1--1--2--1): Level E (C--1--2): Level C (C--1--2--1): Level D (C--2): Level B