## Natural Language Toolkit: sql.fcfg
##
## Deliberately naive string-based grammar for 
## deriving SQL queries from English
## 
## Author: Ewan Klein <ewan@inf.ed.ac.uk> 
## URL: <http://nltk.sourceforge.net>
## For license information, see LICENSE.TXT

% start S

S[sem=(?np + ?vp)] -> NP[sem=?np] VP[sem=?vp]

VP[sem=(?v + ?pp)] -> IV[sem=?v] PP[sem=?pp]
VP[sem=(?v + ?np)] -> TV[sem=?v] NP[sem=?np]

NP[sem=(?det + ?n)] -> Det[sem=?det] N[sem=?n]
NP[sem='Country="japan"'] -> 'Japan'
NP[sem='Country="united_states"'] -> 'USA'

Det[sem='SELECT'] -> 'Which'
N[sem='City FROM city_table'] -> 'cities'

IV[sem='WHERE'] -> 'are'
PP[sem=?np] -> P[sem=?p] NP[sem=?np]
P -> 'in'