The first of these implications follows from (14), the second is a matter of notation. The third implication is an instance of (15), and the next comes from purity. The sixth implication in the derivation follows from (60), and the last is by (54). This s (0)

by F
Venue:free − 8) ↦→ t1, t2) ∗ (scan ↦→ free − 8