KIF Expression Grammar

variable

indvar
| seqvar

operator

termop
| sentop
| defop

termop

"value"
| "listof"
| "quote"
| "if"

sentop

"holds"
| "="
| "/="
| "not"
| "and"
| "or"
| "=>"
| "<="
| "<=>"
| "forall"
| "exists"

defop

"defobject"
| "defunction"
| "defrelation"
| "deflogical"
| ":="
| ":->"
| ":<="
| ":=>"

constant

word

term

indvar
| constant
| charref
| string
| block
| quoterm

quoterm

( "\\(" "quote" listexpr "\\)" )
| ( "'" listexpr )

listexpr

atom
| ( "\\(" listexpr * "\\)" )

atom

word
| charref
| string
| block