diff --git a/src/connectivity.jl b/src/connectivity.jl
index 12975c6a..574b9e6c 100644
--- a/src/connectivity.jl
+++ b/src/connectivity.jl
@@ -96,19 +96,3 @@ function connectivity_sparsematrixcsc(
     end
     return sparse(I, J, V, m, n)
 end
-
-function connectivity_bitmatrix(xt::AbstractArray{Tracer}, yt::AbstractArray{<:Number})
-    # Construct connectivity matrix of size (ouput_dim, input_dim)
-    n, m = length(xt), length(yt)
-    C = BitArray(undef, m, n)
-    for i in axes(C, 1)
-        if yt[i] isa Tracer
-            for j in axes(C, 2)
-                C[i, j] = j ∈ yt[i].inputs
-            end
-        else
-            C[i, :] .= 0
-        end
-    end
-    return C
-end
diff --git a/src/operators.jl b/src/operators.jl
index cde0a784..f3da03e7 100644
--- a/src/operators.jl
+++ b/src/operators.jl
@@ -7,6 +7,8 @@ ops_2_to_1 = (
     :div, :fld, :cld, 
     # modulo
     :mod, :rem,
+    # trigonometric functions
+    :atan, :atand,
     # exponentials
     :ldexp, 
     # sign
@@ -83,7 +85,7 @@ for fn in (:eps, :nextfloat, :floatmin, :floatmax, :maxintfloat, :typemax)
     @eval Base.$fn(::Tracer) = EMPTY_TRACER
 end
 
-## Rounding
+## Rounding with RoundingMode
 Base.round(t::Tracer, ::RoundingMode; kwargs...) = t
 
 ## Random numbers