`usual`for matrices with real or complex entries.`polynomial`for polynomial matrices: coefficients can be real or complex.`boolean`for boolean matrices.`character`for matrices of character strings.`function`for functions.`rational`for rational matrices (`syslin`lists)`state-space`for linear systems in state-space form (`syslin`lists).`sparse`for sparse constant matrices (real or complex)`boolean sparse`for sparse boolean matrices.`list`for ordinary lists.`tlist`for typed lists.`state-space (or rational)`for syslin lists.`library`for library definition.