A fundamental rule or principle.
The principle that one should treat other people in the manner in which one would want to be treated by them.
A method of statutory interpretation, whereby a judge will deviate from a literal interpretation of the law to the extent necessary to circumvent obvious absurdities or (sometimes) conclusions repugnant to public policy.
A syntactically correct expression that is deducible from the given axioms of a deductive system.
A mathematical statement of some importance that has been proven to be true. Minor theorems are often called propositions. Theorems which are not very interesting in themselves but are an essential part of a bigger theorem's proof are called lemmas.
A mathematical statement that is expected to be true
To formulate into a theorem.