RELATION, CONTEXT, CONTAINS. All reserved words are written in capital letters. They are introduced on the fly. You will find an exhaustive list of reserved words at the end of this page."Peter" or "KD-686-D". If you want to introduce a double quote inside an atom, escape it with a backslash, e.g. "the symbol \" is called double quote".
Numeric atoms always start with a digit, e.g. 4711 or 75.88E3. The boolean atoms are TRUE and FALSE. Dates and timestamps follow the Excel-syntax, e.g. ??? The atom _SESSION indicates the current user session, and is an instance of concept SESSION. It is used in services.( and ). For populations and services we use square brackets [ and ].PATTERN and ENDPATTERN, and CONTEXT and ENDCONTEXT.--. Everything after a -- symbol is ignored until the line ends. Multiline comments are wrapped between comment brackets {- and -}. Multiline comments may be nested.Person, Case, A, and Order. Relation names start with a lower case letter, as in contains, attr, sessionLogin, or r.= (equal)\/ (union), /\ (intersect), - (difference); (composition), ! (relational addition), \ (right residual), / (left residual), <> (diamond operator)- (complement), ~ (converse)r/\s\/t is not allowed. You have to write either (r/\s)\/t or r/\(s\/t). Across categories, you may omit brackets because a higher precedence binds stronger. So r;s\/t means (r;s)\/t. (Note that (r;s)\/t and r;(s\/t) have different meanings). Associative operators (\/, /\, ;) need not be disambiguated with brackets. So r\/s\/t and (r\/s)\/t and r\/(s\/t) all mean exactly the same.PRAGMAUNIINJSURTOTSYMASYTRNRFXIRFPROPCONTAINSRULEMESSAGEVIOLATIONTXTSRCTGTIVONEROLEMAINTAINSINTERFACEFORLINKTOBOXVIEWENDVIEWDEFAULTTEMPLATEHTMLCLASSIFYISAISREPRESENTTYPEALPHANUMERICBIGALPHANUMERICHUGEALPHANUMERICPASSWORDBINARYBIGBINARYHUGEBINARYDATEDATETIMEBOOLEANINTEGERFLOATAUTOINCREMENTTRUEFALSE --for booleans_SESSIONONESESSIONSERVICEEDITSSPECKEYPROCESSENDPROCESS