Internal (core) xslt and xpath functions are available for evaluating the attributes of xslt programming elements, as discussed in Appendix C. Version 1.0 functions are implemented in standard xsl processors and web browsers. Xslt functions are shown in Table D.1, xpath functions of interest in numerical computation are shown in Table D.2, xpath functions of general interest are shown in Table D.3, and xpath functions for string manipulation are shown in Tables D.4 and D.5. Detailed explanations on the precise syntax and usage of these functions can be found in xsl texts and Internet tutorials.