Arm64
If the installer is running on an ARM Aarch64-bit processor, the installer sets this variable to 1. If the installer is running on another processor, this variable is set to 0.
Usage
You can refer to it as <Arm64>. In conditional expressions you can omit the brackets and use tests like Arm64 to test for the presence of an ARM 64-bit processor. Do not set this variable directly; it is set automatically when the installer runs.