Lambda Calculus Grammar

<DO_NOT_ADD_RULE>::==<LPAREN><RPAREN><DOT><LAMBDA><ASSIGN><EOF><EMPTY>

<PROGRAM>::==<MACRO><ASSIGN><EXPRESSION_LIST>
<PROGRAM>::==<EXPRESSION_LIST>

<EXPRESSION_LIST>::==<LPAREN><EXPRESSION_LIST><RPAREN><EXPRESSION_LIST>
<EXPRESSION_LIST>::==<EXPRESSION><EXPRESSION_LIST>
<EXPRESSION_LIST>::==<EOF>
<EXPRESSION_LIST>::==<EMPTY>

<EXPRESSION>::==<MACRO>
<EXPRESSION>::==<VARIABLE>
<EXPRESSION>::==<ABSTRACTION>

<ABSTRACTION>::==<LAMBDA><VARIABLE><DOT><EXPRESSION_LIST>

<MACRO>::==MACRO

<EMPTY>::==EMPTY
<EOF>::==EOF
<VARIABLE>::==VARIABLE

<ASSIGN>::==ASSIGN
<LAMBDA>::==LAMBDA
<DOT>::==DOT
<LPAREN>::==LPAREN
<RPAREN>::==RPAREN

EMPTY:=^()\s*
EOF:=^()$
MACRO:=^([A-Z\-]+)\s*
ASSIGN:=^(=)\s*
LAMBDA:=^(λ)\s*
LAMBDA:=^(\^)\s*
DOT:=^(\.)\s*
VARIABLE:=^([a-z\-]+)\s*
LPAREN:=^(\()\s*
RPAREN:=^(\))\s*