Paste: matrix inversion

{ 0.5 0.5 0.0 } translation-matrix4
{ 0.0 0.0 1.0 } pi 0.5 * rotation-matrix4 m.
dup inverse m.

{ { 1.0 0.0 0.0 0.0 }
  { 0.0 1.0 0.0 -0.4... }
  { 0.0 0.0 1.0 0.0 }
  { 0.0 0.0 0.0 1.0 } }