Function: contract (<expr>) Carries out the tensorial contractions in <expr> which may be any combination of sums and products. This function uses the information given to the
defcon function. For best results,
expr should be fully expanded.
ratexpand is the fastest way to expand products and powers of sums if there are no variables in the denominators of the terms. The
gcd switch should be
false if GCD cancellations are unnecessary.
There are also some inexact matches for
?? contract to see them.
(%o1) true (%i2)