ns1 == ns2 => 0
ns1 != ns2 => 1
ns1 == ns1 => 1
ns1 != ns1 => 0
fn1 == fn2 => 0
fn1 != fn2 => 1
fn1 == fn1 => 1
fn1 != fn1 => 0
nil1 == nil2 => 1
nil1 != nil2 => 0
nil1 == nil1 => 1
nil1 != nil1 => 0
cons1 == cons2 => 1
cons1 != cons2 => 0
cons1 == cons1 => 1
cons1 != cons1 => 0