Let , , ...be Operators. Then the commutator of and is
defined as

(1) |

(2) | |||

(3) | |||

(4) | |||

(5) | |||

(6) | |||

(7) | |||

(8) |

The commutator can be interpreted as the ``infinitesimal'' of the commutator of a Lie Group.

Let and be Tensors. Then

(9) |

© 1996-9

1999-05-26