Important: The student package has been deprecated. Use the superseding package Student instead.

The function powsubs differs from subs in that it is defined in terms of algebraic factors rather than in terms of an underlying data structure. Each sub-expression is examined and if $\mathrm{s1}$ occurs as a factor of that sub-expression, the substitution is carried out.  However, powsubs cannot find expressions which only occur as part of a sum.

If more than one substitution is specified they are processed in order from left to right. powsubs does not carry out simultaneous substitutions.

The command with(student,powsubs) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{student}\right)\:$

$p≔{\left(x+2\right)}^3+\frac{1}{x+2}+\sin \left(x+2\right)$

$p≔{\left(x+2\right)}^3+\frac{1}{x+2}+\sin \left(x+2\right)$

$\mathrm{powsubs}\left(x+2=z\,p\right)$

$z^3+\frac{1}{z}+\sin \left(z\right)$

$q≔\mathrm{sqrt}\left(x^2+y^2\right)+f\left(x^2+y^2\right)+\mathrm{Int}\left(x^2+y^2\,x\right)$

$q≔\sqrt{x^2+y^2}+f\left(x^2+y^2\right)+\int \left(x^2+y^2\right)\ⅆx$

$\mathrm{powsubs}\left(x^2+y^2=z\,q\right)$

$\sqrt{z}+f\left(z\right)+\int z\ⅆx$