We explain the construction of Forcer, a FORM program for the reduction of four-loop massless propagator-type integrals to master integrals. The resulting program performs parametric IBP reductions similar to the three-loop Mincer program. We show how one can solve many systems of IBP identities parametrically in a computer-assisted manner. Next, we discuss the structure of the Forcer program, which involves recognizing reduction actions for each topology, applying symmetries, and transitioning between topologies after edges have been removed. This part is entirely precomputed and automatically generated. We give examples of recent applications of Forcer, and study the performance of the program. Finally we demonstrate how to use the Forcer package and sketch how to prepare physical diagrams for evaluation by Forcer.

中文翻译：

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Forcer，一个用于四环无质量传播器图参数化约的 Form 程序

我们解释了 Forcer 的构造，这是一个 FORM 程序，用于将四环无质量传播器类型的积分简化为掌握积分。生成的程序执行类似于三循环 Mincer 程序的参数化 IBP 降低。我们展示了如何以计算机辅助的方式参数化地解决许多 IBP 身份系统。接下来，我们讨论 Forcer 程序的结构，它涉及识别每个拓扑的归约动作、应用对称性以及在去除边后拓扑之间的转换。这部分完全是预先计算和自动生成的。我们举例说明了 Forcer 的最新应用，并研究了该程序的性能。最后，我们演示了如何使用 Forcer 包并概述如何准备物理图以供 Forcer 评估。