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#### Search: #### Contract

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`. Try `?? contract` to see them.

```(%o1)                                true
(%i2) ```

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