Is it possible to infer B from (A ⊃ B) ⊃ B and (A ⊃ B)? Intuitively, the argument seems valid. However, I'm not sure whether this is indeed case; also, it is not clear to me whether (A ⊃ B) ⊃ B is a tautology or not, and whether this (i.e. (A ⊃ B) ⊃ B being a tautology) would affect the validity of the argument.
2026-04-23 20:36:47.1776976607
Basic logic: inferring B from (A ⊃ B) ⊃ B and (A ⊃ B)
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The argument is valid, and whether or not one of the statements is a tautology has no bearing on validity.
In fact $(A \supset B) \supset B$ is not a tautology. This can be checked via the method of truth tables; in particular, if $A$ and $B$ are both false, $(A \supset B)$ is true, so $(A \supset B) \supset B$ is false.