Maxima Function
defcon (tensor_1)
defcon(tensor_1,tensor_2,tensor_3)
gives tensor_1 the property that the
contraction of a product of tensor_1 and tensor_2 results in tensor_3
with the appropriate indices. If only one argument, tensor_1, is
given, then the contraction of the product of tensor_1 with any indexed
object having the appropriate indices (say my_tensor
) will yield an
indexed object with that name, i.e. my_tensor
, and with a new set of
indices reflecting the contractions performed.
For example, if imetric:g
, then defcon(g)
will implement the
raising and lowering of indices through contraction with the metric
tensor.
More than one defcon
can be given for the same indexed object; the
latest one given which applies in a particular contraction will be
used.
contractions
is a list of those indexed objects which have been given
contraction properties with defcon
.