# Tagged Questions

Questions about truth tables, conjunctive and disjunctive normal forms, negation, and implication of unquantified propositions would fit very nicely under this tag. Questions about other kind of logics should be tagged with [logic] instead.

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### Showing that $(A \land B)' \land (C' \land A)' \land (C \land B')' \to A'$ without a truth table

Problem: Prove that $(A \land B)' \land (C' \land A)' \land (C \land B')' \to A'$. What I have done so far: $(A \land B)'$ premise $(C' \land A)'$ premise $(C \land B')'$ premise $A' \lor B'$ 1, ...
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### Proofs Using Tautologies

Let's say I want to formally prove a statement of the form $$p \implies q$$ So I do a bit of work,some re-arranging and eventually I arrive at a statement of the form $$p \implies p$$ which is a ...
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### Logic Behind Epsilon-Delta Proofs (Single-Variable Calculus)

Most of what I am asking is based off this (fairly popular) article I've read here : https://bobobobo.wordpress.com/2008/01/20/how-to-do-epsilon-delta-proofs-1st-year-calculus/, but most lecturers, ...
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### Progressing in Propositional Logic

I am self-studying precalculus-level mathematics in perhaps a more formal way than usual, which means that I am reading about logic, sets, proofs, etc. The text I am looking at contains as an example ...
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### Resolution proof involving more than a literal

I want to show that the following clauses are unsatisfiable together using resolution (i.e. obtain a refutation): 1: $\lnot P_1 \lor \lnot P_2$ 2: $P_2 \lor \lnot P_3$ $P_1 \land P_3$ I perform ...
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### conditional proposition vs biconditional proposition

So I have been working on college and am currently in a math class. The following question came up and I chose "->" as the answer. This was marked wrong and I challenged the answer but was told this ...
I'm having trouble understanding the following problem: Let $S_n$ be the set of all formulas that can be built up with the atoms $\{A_1,...,A_n\}$. How many equivalence classes does the ...