| 1: | app(app(rec,h),app(g,0)) | → g | |
| 2: | app(app(rec,h),app(g,app(s,x))) | → app(app(h,x),app(app(rec,h),app(g,x))) | |
| 3: | APP(app(rec,h),app(g,app(s,x))) | → APP(app(h,x),app(app(rec,h),app(g,x))) | |
| 4: | APP(app(rec,h),app(g,app(s,x))) | → APP(h,x) | |
| 5: | APP(app(rec,h),app(g,app(s,x))) | → APP(app(rec,h),app(g,x)) | |
| 6: | APP(app(rec,h),app(g,app(s,x))) | → APP(g,x) | |