diff --git a/engine-proto/engine.jl b/engine-proto/engine.jl
new file mode 100644
index 0000000..8b82b47
--- /dev/null
+++ b/engine-proto/engine.jl
@@ -0,0 +1,34 @@
+module Engine
+
+export Construction, Sphere, mprod, point
+
+using LinearAlgebra
+using Groebner
+
+mutable struct Construction
+  nextid::Int64
+  
+  Construction(; nextid = 0) = new(nextid)
+end
+
+struct Sphere{T<:Number}
+  vec::Vector{T}
+  id
+  
+  function Sphere(vec::Vector{T}, ctx::Construction) where T <: Number
+    id = ctx.nextid
+    ctx.nextid += 1
+    new{T}(vec, id)
+  end
+end
+
+function mprod(sv::Sphere, sw::Sphere)
+  v = sv.vec
+  w = sw.vec
+  v[1]*w[2] + v[2]*w[1] - dot(v[3:end], w[3:end])
+end
+
+point(pt::Vector{<:Number}, ctx::Construction) =
+  Sphere([one(eltype(pt)), dot(pt, pt), pt...], ctx)
+
+end
\ No newline at end of file