21. An apparatus comprising: a computing device, the computing device to: transform between at least first and at least second non-transitory stored binary digital signal quantities respectively representing at least a first and at least a second expression, said represented expressions to have a common view for non-common expression types of said represented expressions and to have a non-common view for common expression types of said represented expressions, said represented expressions to comprise at least one of the following expression types: a hierarchical edge and/or node labeled tree or a symbol string.
27. The apparatus of claim 21 , wherein said computing device to employ operations with respect to said first represented expression subsequent to said transformation.