I'm unsure if this method of natural deduction is correct.
To prove: $P \vee F,\; \neg T \mathbin\rightarrow \neg P,\; T \mathbin\rightarrow B,\; \neg F \;\vDash\; B$
Proof:
- $P \vee F$ (Data)
- $\neg T \mathbin\rightarrow \neg P$ (Data)
- $T \mathbin\rightarrow B$ (Data)
- $\neg F$ (Data)
- $\neg T \mathbin\rightarrow P$ (subcomp box)
- $\neg T$ (Assume P)
- $P$ (from 1,4,($\vee$E2))
- $T$ from (2,5,($\neg$E))
- $B$ from (3,6,($\mathbin\rightarrow$E))
I tried to solve using this method; I'm not sure if it is correct.