added by an implicit conversion from <a href="" name="provingground.learning.ExpressionEquationSolver.FixedExpressionProbs" id="provingground.learning.ExpressionEquationSolver.FixedExpressionProbs" class="extype">FixedExpressionProbs</a> to<span name="scala.Predef.ArrowAssoc" class="extype">ArrowAssoc</span>[<a href="" name="provingground.learning.ExpressionEquationSolver.FixedExpressionProbs" id="provingground.learning.ExpressionEquationSolver.FixedExpressionProbs" class="extype">FixedExpressionProbs</a>] 