Subproofs Flashcards
1
Q
What do we open a subproof with?
A
A hypothesis
2
Q
What does a hypothesis need?
A
A justification annotation
3
Q
What do we put immediately below the hypothesis?
A
A horizontal line
4
Q
When we finish a subproof that started with X and ended with Y, what must the content of the next line be?
A
X -> Y, justified by the conditional introduction rule ->I
5
Q
When a subproof is finished, and we’ve written the conditional as the next line, that subproof is what?
A
Closed
6
Q
In subsequent lines of the proof, we are not allowed to use what?
A
Anything that was proved within that closed subproof (i.e. our justifications cannot cite any lines within that subproof).
7
Q
We can start a subproof when?
A
At any point during the proof, even while we’re in the middle of another subproof
