| The idea haunted him like the invertible companions of Orestes. |
| He spent about a year of rigorous self-study fooling around with canons, fugues, invertible counterpoint, and so on. |
| It was Gardner who first showed me the invertible signatures designed by Scott Kim. |
| What follows is not a strict fugue, but a fugato in five-part invertible counterpoint. |
| The cryptographic problem is that the combining operation used to determine successive states in the sequence is linear and hence easily invertible, even though the sequence can be 2n − 1 bits in length before repeating. |
| Projective transformations, which are invertible linear changes of homogeneous coordinates, are given by matrix multiplication. |
