lazy val Pushout4 = category"Pushout4:({a,b,c,d,e}, {ab: a → b, ac: a → c, ad: a → d, ae: a → e})" lazy val Square = category"Square:({a,b,c,d}, {ab: a → b, ac: a → c, bd: b → d, cd: c → d, ad: a → d}, {bd ∘ ab = ad, cd ∘ ac = ad})"