In fact the discrete integrable system can be used as the model of some problem in physics, chemistry and biology, for example the Toda lattice equation and the Volterra lattice equation.

• 众所周知，在物理学、化学及生物学中的许多些现象是以微分-差分方程作为模型建立起来的，如Toda晶格方程和Volterra晶格方程等。