Test 2 LOG

Theorem

A statement from that can be proved without any given premises

Justified step

Either a premise, or an assumption, or a step that follows from previous step according to one of the given rules of inference

Proof

Sequence of justified steps in which last step is desired conclusion; that is, it is a sequence of steps, each of which is either a premise, or an assumption, or a step that follows from previous steps according to one of the given rules of inference and in which the last step is the desired conclusion

Statement variable

Letter that can take as a substitution instance any particular statement, simple or complex

Statement constant

Capital letter that is used as an abbreviation for a particular truth functionally simple English sentence

Statement

Formular that has statement constants as its smallest components

Statement form

Formula that has statement variables as its smallest components

Substitution instance

Statement form is a statement obtained by substituting some statement for each variable in the statement form

Derivation

Sequence of justified steps

Proof

Derivation in which last step is desired conclusion