At: assignment monotone 1 1 4 1 1 1 1 1
1. f: Formula
2. x1: Formula
3. x2: Formula
4. a: Assignment
5. a': Assignment
6. a' extends a
7. a |= x1 
a' |= x1
8. a |
x1 
a' |
x1
9. a |= x2 
a' |= x2
10. a |
x2 
a' |
x2
11. a |= x1

x2
12. a |= x1
a' |= x1
a' |= x2
By:
Choose [1]
THEN
HypBackchain
Generated subgoals:None
About: