Introduction to Proofs

Truth tables are an extremely inefficient method for checking the validity of a logical argument. Proofs are less algorithmic but are much faster to complete.

Takeaway Points

  1. Proofs begin with premises. In homework assignments, you will usually be given a conclusion that you need to find using those premises.
  2. You may use rules of replacement or inference on any line above the current line.
  3. All lines must cite their reasoning.
  4. The last line should be what you are trying to prove.
  5. Proofs in academic work are much harder because you often have to prove individual premises on your own and you are often unsure what you are trying to prove.

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