To run Scheme-based reduction semantics:
- Install DrScheme version 301.
- Download redsem.plt and save it as a file.
- Open your downloaded reduction-semantics.plt with DrScheme, and allow DrScheme to install it.
- In DrScheme, select the Choose Language item in the Language menu. In the dialog that appears, turn down the PLT arrow and select Graphical (MrEd).
- In DrScheme, open a reduction-semantics program (such as r.scm) and click the Execute button.