| sentence | ::= module : sentence |
| | list | { where list is a list of sentence } |
| | clause |
| | directive |
| | query |
| | grammar-rule |
|
| clause | ::= rule | unit-clause |
|
| rule | ::= head :- body |
|
| unit-clause | ::= head | { where head is not otherwise a sentence } |
|
| directive | ::= :- body |
|
| query | ::= ?- body |
|
| head | ::= module : head |
| | goal | { where goal is not a variable } |
|
| body | ::= module : body |
| | body -> body disj body |
| | body -> body |
| | \+ body |
| | body disj body |
| | body , body |
| | once(body) |
| | do(iter,body) |
| | if(body,body,body) |
| | term ^ body |
| | goal |
|
| goal | ::= term | { where term is not otherwise a body } |
|
| grammar-rule | ::= gr-head --> gr-body |
|
| gr-head | ::= module : gr-head |
| | gr-head , terminals |
| | non-terminal | { where non-terminal is not a variable } |
|
| gr-body | ::= module : gr-body |
| | gr-body -> gr-body disj gr-body |
| | gr-body -> gr-body |
| | \+ gr-body |
| | gr-body disj gr-body |
| | gr-body , gr-body |
| | once(gr-body) |
| | do(iter,gr-body) |
| | if(gr-body,gr-body,gr-body) |
| | term ^ gr-body |
| | non-terminal |
| | terminals |
| | gr-condition |
|
| non-terminal | ::= term | { where term is not otherwise a gr-body } |
|
| terminals | ::= list | string |
|
| gr-condition | ::= ! | {body} |
|
| module | ::= atom |
|
| disj | ::= ; | | | { read as ; unless | is declared infix } |
|
| iter | ::= iter , iter |
| | fromto(term,term,term,term) |
| | foreach(term,term) |
| | foreacharg(term,term) |
| | foreacharg(term,term,term) |
| | count(term,term,term) |
| | for(term,term,term) |
| | param(term) |