\File{figureB\-19.ry},{02:05},{Jan 26 1990}
\L{\LB{\C{}\-\- operations}}
\CE{}\L{\LB{}}
\L{\LB{evalOperation \K{OPERATION}}}
\L{\LB{    \K{ARGUMENT}}\Tab{16}{EvalObject}}
\L{\LB{    \K{RESULT}}\Tab{16}{EvalObject}}
\L{\LB{    \K{ERRORS}}\Tab{16}{\{ evalError \}}}
\L{\LB{    \K{LINKED}}\Tab{16}{\{ read, write \}}}
\L{\LB{}\Tab{8}{::= 0}}
\L{\LB{}}
\L{\LB{read \K{OPERATION}}}
\L{\LB{    \K{RESULT}}\Tab{16}{EvalObject}}
\L{\LB{    \K{ERRORS}}\Tab{16}{\{ endOfInput \}}}
\L{\LB{}\Tab{8}{::= 1}}
\L{\LB{}}
\L{\LB{write \K{OPERATION}}}
\L{\LB{    \K{ARGUMENT}}\Tab{16}{EvalObject}}
\L{\LB{}\Tab{8}{::= 2}}
\L{\LB{}}
\L{\LB{\C{}\-\- errors}}
\CE{}\L{\LB{}}
\L{\LB{evalError \K{ERROR}}}
\L{\LB{    \K{PARAMETER}}\Tab{16}{Service\-Diagnostic}}
\L{\LB{}\Tab{8}{::= 0}}
\L{\LB{}}
\L{\LB{endOfInput \K{ERROR}}}
\L{\LB{}\Tab{8}{::= 1}}
\L{\LB{}}
\L{\LB{...}}
