prelude
definition Prop : Type.{1} := Type.{0}
constants a b c : Prop
axiom Ha : a
axiom Hb : b
axiom Hc : c
#check
  have H1 : a, from Ha,
  have H2 : a, from H1,
  have H3 : a, from H2,
  have H4 : a, from H3,
  H4
