Is $A^{-1}+B^tAB$ invertible if $A$ and $B$ are invertible?

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Let $A$ and $B$ be invertible matrices of the same size with $A$ symmetric and $B$ skew-symmetric. Is $A^{-1}+B^tAB$ invertible as well? And, if it is, can its inverse be expressed in terms of $A$ and $B$?

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Try $A=\pmatrix{1&0\\0&-1}$ and $B=\pmatrix{0&-1\\1&0}$.