A Proof that Souslin Souslin H ⊂ Souslin H
S. Simons · Canadian Mathematical Bulletin · 1966
We write ω for the set of natural numbers (including zero) and for the set of all finite sequences of natural numbers. If n ∊ ω we write . If x is a function which takes its values in cu and whose domain of definition contains then we write for the element (x(0), …, x(n)) of .