You will enter your courses and letter grades individually in the AMCAS application. The AAMC doesn't know or care whether your institution considers an A- to be a 3.6 or 3.7; it will calculate them using the values listed in the PDF above.
The AMCAS calculates your GPA based on all your individual courses with no regard to what your school considers your GPA to be.
AMCAS will use your college transcripts to individually verify each entered course.
On an unrelated note, I've never seen that A/AB/B/BC style grading scheme before. I like that a lot more than having + and - grading.