Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
Function: defcon (<tensor_1>)
Function: 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.
(%o1) true (%i2)