From 759137328ab1ee137370e6c06e97e9f3a37dc90e Mon Sep 17 00:00:00 2001
From: Chris Rackauckas <accounts@chrisrackauckas.com>
Date: Fri, 7 Feb 2020 15:44:29 -0500
Subject: [PATCH] add ambiguity fixes

---
 Project.toml         | 2 +-
 src/differentials.jl | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index 9af1ac1436..ef621c6124 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ModelingToolkit"
 uuid = "961ee093-0014-501f-94e3-6117800e7a78"
 authors = ["Chris Rackauckas <accounts@chrisrackauckas.com>"]
-version = "1.2.1"
+version = "1.2.2"
 
 [deps]
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
diff --git a/src/differentials.jl b/src/differentials.jl
index 955a715475..0faf4233d9 100644
--- a/src/differentials.jl
+++ b/src/differentials.jl
@@ -110,6 +110,8 @@ for (modu, fun, arity) ∈ DiffRules.diffrules()
 end
 
 derivative(::typeof(+), args::NTuple{T,Operation}, ::Val{i}) where {T,i} = args[i]
+derivative(::typeof(+), args::Tuple{Operation,Operation}, ::Val{1}) = args[1]
+derivative(::typeof(+), args::Tuple{Operation,Operation}, ::Val{2}) = args[2]
 
 function count_order(x)
     @assert !(x isa Symbol) "The variable $x must have an order of differentiation that is greater or equal to 1!"