%and%	and
%not%	not
%or%	or
and	and
combination	combination
grep	grep
grepl	grepl
grepl_and	grepl
grepl_not_and	grepl
grepl_not_or	grepl
grepl_or	grepl
grep_and	grep
grep_not_and	grep
grep_not_or	grep
grep_or	grep
not	not
or	or
