:- op(10, fy, ~). :- op(20, yfx, &). :- op(30, yfx, v). :- op(40, xfx, =>). :- op(40, xfx, <=>). :- initialization( logtalk_load([ translator])). /* If you intend to use the FOP XSL:FO processor for generating PDF documenting files, comment the directive above and uncomment the directive below :- initialization( logtalk_load( [translator], [xmlsref(standalone)])). */