15B33 6 15A30 5 Hasse diagram 2 commutative ring 2 minimax equivalence 2 quadratic Tits form 2 similarity 2 15A21 1 2-monomial matrix 1 Dynkin diagram 1 Jacobson radical 1 Kleiner's poset 1 Tits \(P\)-critical poset 1 Tits quadratic form 1 \(0\)-balanced subposet 1 \(P\)-critical poset 1 canonically \(t\)-cyclic matrix 1 defining sequence 1 direct sum of posets 1 equivalent matrices modulo an ideal 1 free module 1 group 1 hereditary reducible matrix 1 indecomposable matrix 1 irreducible matrix 1 linear operator 1 local ring 1 minimax sum 1 one-side and two-side sums 1 perfect \((I,J)\)-matrix 1