Function vstd::set_lib::lemma_len_union

source · 
pub proof fn lemma_len_union<A>(s1: Set<A>, s2: Set<A>)
Expand description
requires
s1.finite(),
s2.finite(),
ensures
s1.union(s2).len() <= s1.len() + s2.len(),

The size of a union of two sets is less than or equal to the size of both individual sets combined.