⌜# x⌝ = # ⌜x0⌝ , ∀ n. n < # x → x[n] = ⌜x0⌝ [n] ⊦ ⌜x⌝ = ⌜x0⌝
Used simplifier rules: size-inf: ⊦ # ⌜nf⌝ = ∞;%stream freely generated by ⌜ ⌝, ⌜ ⌝;;%disj: ⊦ ⌜m⌝ ≠ ∞; from specification nat-inf-basic