Leibniz rule and exact supersymmetry on lattice: a case of   supersymmetrical quantum mechanics
  We propose a new formulation of lattice theory. It is given by a matrix form and suitable for satisfying Leibniz rule on lattice. The theory may be interpreted as a multi-flavor system. By realizing the difference operator as a commutator, we may obtain exact supersymmetric theories on lattice explicitly. Some problems such as locality and single flavor reduction are also commented. 
Mitsuhiro Kato, Makoto Sakamoto and Hiroto So