techniques are provided for performing focus inference when compiling an extensible markup language transforms stylesheet into a compiled xslt processor . in xpath / xslt , expression evaluation occurs with respect to the dynamic context . in xpath , the part of the dynamic context , related to the context node - set , is called the “ focus ” of the expression . conceptually , the focus would need to be systematically computed and propagated along the recursive execution of xslt templates . this is costly . focus inference enables the more efficient execution of xslt programs since the inferred focus information can be used directly by a code generator in an xslt compilation architecture .