(databases) A stage in the normalization of a relational database in which a database is in second normal form and all non-key attributes are mutually independent (no transient dependencies.)

(databases) A stage in the normalization of a relational database in which a database is in fourth normal form and every join dependency is implied by the candidate keys.

(databases) A stage in the normalization of a relational database in which repeating groups and attributes have been eliminated by putting each into a separate table connected by a primary-key/foreign-key relationship.

(game theory) Informally, a representation of a game as a tree of decision nodes, with the game beginning at a unique initial node, and flowing through the tree along a path determined by the players until a terminal node is reached, where play ends and payoffs are assigned to all players; each non-terminal node belongs to a player; that player chooses among the possible moves at that node, each possible move is an edge leading from that node to another node.

(game theory) Formally, a structure (P, mathbf S, mathbf F) where P = {1,2, ...,m} is a set of players, mathbf S=(S_1,S_2,…,S_m) is an m-tuple of pure strategy sets, one for each player, and mathbf F=(F_1,F_2,…,F_m) is an m-tuple of payoff functions.

(linear algebra) The stepped appearance of a matrix that has undergone Gaussian elimination with the result that the leading coefficient or pivot (that is, the first nonzero number from the left) of a nonzero row is to the right of the pivot of the row above it.

(linear algebra) The transpose of the row echelon form of the transpose of a given matrix.

(optics) A lens that is designed to minimize spherical aberration.

plural of best form lens

(logic) The form of a boolean formula that the formula has if the formula is a disjunction of conjunctions of literals, such as “(A and B and C) or (D and E and not F)”.