Tautological has the “common” meaning of trivial and in logic is a technical term:
What are tautological statements?
1a : needless repetition of an idea, statement, or word Rhetorical repetition, tautology (‘always and for ever’), banal metaphor, and short paragraphs are part of the jargon.— Philip Howard. b : an instance of such repetition The phrase “a beginner who has just started” is a tautology.
What is tautological truth?
A Tautology is a statement that is always true because of its structure—it requires no assumptions or evidence to determine its truth. A tautology gives us no genuine information because it only repeats what we already know.
What does consistency mean in logic?
Logical consistency. Definition: a set of sentences is logically consistent if and only if it is possible for all the members of that set to be true. A consistent set of sentences is a set all of which can be true together — or, as logicians are fond of saying: there is some possible world in which they are all true.
What is consistency in propositional logic?
Two or more propositions are logically consistent if it is possible for them to all be true at the same time. If there is no way for them all to be true at once, they are inconsistent . Inconsistent propositions are said to contradict one another.
What is tautology and contradiction?
A tautology is an assertion of Propositional Logic that is true in all situations; that is, it is true for all possible values of its variables. A contradiction is an assertion of Propositional Logic that is false in all situations; that is, it is false for all possible values of its variables.