The default simplifying function is normal . A summed index is an index that appears two times, one with positive sign and another with negative sign. The free indices are not substituted by numerical ones in this case. The result of sumt is a tensor expression which can be used as arguments of some functions of the Riemann package for further component calculation. The parameter x can be a name or a tensor whose components are names.
Any function beginning with t is an inert function to functions evalt and calc .
The first letter t will be taken away by these functions. This function does not assign the results. If f takes more than one argument, they are passed as extra arguments of tmap . The connection name can be changed by assigning a new name to variable ChristoffelName . The parameter x can be a name or a tensor of rank one whose components are names.