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When the **skewcover** configuration variable is true the blowing
up varieties are covered by chart which are obtained by first
describing the blowing up center in some rotated coordinate system
such that in a chart of the covering of the blowing up allows the
elimination of maximal number of variables, i.e. the number of
generators for the *k*-algebra of the new chart remains constant.
The procedure applies such a rotation.

**Input:**-
**S**- the variables of the original chart without
`DEP2V`, **C**- the generators of the nonsingular blowing up center with
`DEP2V`being eliminated from them, **m**- the codimension of the center,
**SR1**- (output parameter) the rotated variables,
**SR2**- (output parameter) the variables with respect to which we
rotated the ones in
*SR1*(the unchanged ones), **SROT**- (output parameter) the equations of the substitution of the rotation,
**ISROT**- (output parameter) the equations of the substitution of the inverse rotation.

**Output:**- The Gröbner basis of the center computed with
elimination order for variables in
*SR2*, after a rotation such that the projection to the subspace of the rotated variables is generically one-to-one.