(physics) A theorem stating that the energy eigenstates for an electron in a crystal can be written as Bloch waves.

(mathematics) A theorem that gives a lower bound on the size of a disc in which an inverse to a holomorphic function exists.

(logic) A theorem stating that, in any formal system F with Peano arithmetic, for any formula P, if it is provable in F that "if P is provable in F then P is true", then P is provable in F.

(computing theory) A theorem that establishes a limit on the extent to which an algorithm can decide whether certain mathematical expressions are equal.

(mathematics) A theorem stating that, if S, is an IP set and S=C_1∪C_2∪...∪C_n, then at least one C_i, contains an IP set.

(graph theory) A theorem stating that, among the n-vertex simple graphs with no (r + 1)-cliques, T(n, r) has the maximum number of edges.

(mathematical analysis) Any of a class of theorems which, for a given Abelian theorem, specifies conditions such that any series whose Abel sums converge (as stipulated by the Abelian theorem) is in fact convergent.

A theorem postulating that all black hole solutions of the Einstein-Maxwell equations in general relativity can be completely characterized by only three externally observable classical parameters: mass, electric charge, and angular momentum.

(logic) The following theorem of Boolean algebra: XY+X'Z+YZ=XY+X'Z where YZ, the algebraically redundant term, is called the "consensus term", or its dual form (X+Y)(X'+Z)(Y+Z)=(X+Y)(X'+Z), in which case Y+Z is the consensus term. (Note: X+Y,X'+Z⊢Y+Z is an example of the resolution inference rule (replacing the + with ∨ and the prime with prefix ¬ might make this more evident).)

(logic) A procedure for "discharging" assumptions from an inference, causing them to become antecedents of the conclusion; or vice versa. Symbolically, the conversion of an inference of the form P,A⊢C to an inference of the form P⊢A→C or vice versa, where ⊢ is the turnstile symbol. The validity of the procedure is a metatheorem of the given logical theory.