Subjects | Variables | Explanation |

Farmer | $C{F}_{i}\left(C{{F}^{\prime}}_{i},C{{F}^{\u2033}}_{i}\right)$ | Production cost of agricultural products, $C{{F}^{\prime}}_{i},C{{F}^{\u2033}}_{i}$ represents production cost of signing the keeping fresh contract and not signing the keeping fresh contract respectively. $i$ expresses different kinds of agricultural products. |

${\gamma}_{1}\in \left[{{\gamma}^{\prime}}_{1},{{\gamma}^{\u2033}}_{1}\right]$ | Effort level to ensure the quality of fresh agricultural products. ${{\gamma}^{\prime}}_{1},{{\gamma}^{\u2033}}_{1}$ represents the minimum and maximum level of effort, both in the 0 - 1. | |

${p}_{i1}\left({{p}^{\prime}}_{i1},{{p}^{\u2033}}_{i1}\right)$ | Wholesale price of agricultural products, ${{p}^{\prime}}_{i1},{{p}^{\u2033}}_{i1}$ represents wholesale price of signing the keeping fresh contract and not signing the keeping fresh contract respectively. | |

Super- market | $C{M}_{i}\left({p}_{i1}\right)$ | Purchase cost of agricultural products, $C{{M}^{\prime}}_{i},C{{M}^{\u2033}}_{i}$ represents purchase cost of signing the keeping fresh contract and not signing the keeping fresh contract respectively. |

${Q}_{i}$ | The total amount of agricultural products purchased. | |

$C{T}_{1}\left(C{{T}^{\prime}}_{1},C{{T}^{\u2033}}_{1}\right)$ | Transportation cost of agricultural products, $C{{T}^{\prime}}_{1},C{{T}^{\u2033}}_{1}$ represents the payment of the cost of transport for logistics company of signing the keeping fresh contract and not signing the keeping fresh contract respectively. | |

${p}_{i2}\left({{p}^{\prime}}_{i2},{{p}^{\u2033}}_{i2}\right)$ | Sales price of agricultural products, ${{p}^{\prime}}_{i2},{{p}^{\u2033}}_{i2}$ represents the sales price of signing the keeping fresh contract and not signing the keeping fresh contract respectively. | |

Logistics company | $C{T}_{2}$ | The transportation cost of logistics company. |

${\gamma}_{2}\in \left[{{\gamma}^{\prime}}_{2},{{\gamma}^{\u2033}}_{2}\right]$ | Effort level to ensure the quality of fresh agricultural products. ${{\gamma}^{\prime}}_{2},{{\gamma}^{\u2033}}_{2}$ represents the minimum and maximum level of effort, both in the 0 - 1. | |

Parameter variable | $\theta \left({\gamma}_{i},{\epsilon}_{1}\right)\in \left[0,1\right]$ | Fresh level of agricultural products, increasing with ${\gamma}_{i}$ , $\theta \left({\gamma}_{i},{\epsilon}_{1}\right)=\theta \left({\gamma}_{i}\right){\epsilon}_{1}$ |

${\epsilon}_{\text{1}}$ | Random variables under uncertain conditions. | |

${K}_{1},{K}_{2}$ | Price elasticity of different price. | |

$\pi F\left(\pi {F}^{\prime},\pi {F}^{\u2033}\right)$ $\pi M\left(\pi {M}^{\prime},\pi {M}^{\u2033}\right)$ $\pi T\left(\pi {T}^{\prime},\pi {T}^{\u2033}\right)$ | Respectively, on behalf of the profit of farmer, supermarket and logistics company in the case of signing the fresh-keeping contract. | |

Consumer | ${\epsilon}_{\text{2}}$ | Random variables under uncertain conditions. |

${D}_{i}\left({p}_{i2},\theta \right)$ | Demand function, is related to fresh level of agricultural products. |