expect_diagonal         Do you expect a matrix to be diagonal?
expect_idempotent       Do you expect a function to be idempotent?
expect_involutory       Do you expect a function to be involutory?
expect_n_idempotent     Do you expect a function to be n-idempotent?
expect_n_involutory     Do you expect a function to be n-involutory?
expect_orthogonal       Do you expect a matrix to be orthogonal?
expect_periodic         Do you expect a function to be periodic?
expect_psd              Do you expect a matrix to be positive
                        semidefinite?
expect_spd              Do you expect a matrix to be symmetric positive
                        definite?
expect_symmetric        Do you expect a matrix to be symmetric?
