/media/sda-magnetic/david/Dokumente-15/fernuni-hagen/cs-i-ii/old-cs-2-01/informatik2/lex-yacc-bash-etc/grammatik03.txt

statement       ::= assigment | cond | loop
assignment      ::= id := expr
cond            ::= if boolexpr then statement fi | if boolexpr then statment else statement fi
while           ::= while boolexpr do statement od
expr            ::= boolexpr | numexpr
boolexpr        ::= numexpr cop numexpr
numexpr         ::= numexpr + term | term
term            ::= term * factor | factor
factor          ::= id | const | (numexpr)