FORMULAI GRIN, formulaest, ki integrali dukarataro ba integrali kajkhatta tabdil medihad; shaklash chunin ast:
in jo S — sohai hamvori mahdudkardai khati kaji K, R va Q — funksiyahoi dutagyiryobanda, integrali tarafi chap az rui khati K muqobili samti harakati aqrabaki soat girifta meshavad. Holati khususii formulai Stoks ast. Onro soli 1828 matematiki anglis J. Grin muqarrar kardaast.