| ⊦ (n ≤ # lax ⊃ firstn(n, lax.to-adr(m));lax.to-adr(m)) = prefixn(n, lax).to-adr(m) |
⊦ prefixn(n, lax) = (n ≤ # lax ⊃ firstn(n, lax);lax)
⊦ (n ≤ # lax ⊃ firstn(n, lax.to-adr(m));lax.to-adr(m)) = (n ≤ # lax ⊃ firstn(n, lax);lax).to-adr(m)
Used terms: lax, n