Exercise algebra.equations.coverup

Description
solve an equation by covering up

Strategy

<label name="cover-up">
  <let>
    <decl var="3">
      <orelse>
        <sequence>
          <let>
            <decl var="1">
              <choice>
                <rule name="algebra.equations.coverup.power"/>
                <rule name="algebra.equations.coverup.plus"/>
                <rule name="algebra.equations.coverup.minus-left"/>
                <rule name="algebra.equations.coverup.minus-right"/>
                <rule name="algebra.equations.coverup.negate"/>
                <rule name="algebra.equations.coverup.times"/>
                <rule name="algebra.equations.coverup.numerator"/>
                <rule name="algebra.equations.coverup.denominator"/>
                <rule name="algebra.equations.coverup.sqrt"/>
                <fail/>
                <sequence>
                  <rule name="navigator.down"/>
                  <succeed/>
                  <let>
                    <decl var="2">
                      <choice>
                        <var var="1"/>
                        <sequence>
                          <rule name="navigator.right"/>
                          <succeed/>
                          <var var="2"/>
                        </sequence>
                      </choice>
                    </decl>
                    <var var="2"/>
                  </let>
                  <orelse>
                    <rule name="navigator.up"/>
                    <succeed/>
                  </orelse>
                </sequence>
              </choice>
            </decl>
            <var var="1"/>
          </let>
          <var var="3"/>
        </sequence>
        <succeed/>
      </orelse>
    </decl>
    <var var="3"/>
  </let>
</label>

Locations