Function negate_clause 

pub fn negate_clause(expr: Expr) -> Expr

negate a Not clause input is the clause to be negated.(args of Not clause) For BinaryExpr, use the negation of op instead. not ( A > B) ===> (A <= B) For BoolExpr, not (A and B) ===> (not A) or (not B) not (A or B) ===> (not A) and (not B) not (not A) ===> A For NullExpr, not (A is not null) ===> A is null not (A is null) ===> A is not null For InList, not (A not in (..)) ===> A in (..) not (A in (..)) ===> A not in (..) For Between, not (A between B and C) ===> (A not between B and C) not (A not between B and C) ===> (A between B and C) For others, use Not clause