Is it always true that (see the attachment)?
I am assuming that phi is a matrix and its elements depend on t, another variable.
In order for this to make sense, [itex]\phi[/itex] would have to be a one-to-one function from a set of matrices onto itself. And it asks if the inverse function, appled to matrix x, is the same as the inverse of [itex]\phi(x)[/itex].
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