update oplus syntax

Author: lkdvos

src/operators/mpohamiltonian.jl

@@ -394,12 +394,13 @@ function Base.:+(H₁::MPOH, H₂::MPOH) where {MPOH<:MPOHamiltonian}
         Vₗ₁ = left_virtualspace(H₁, i)
         Vₗ₂ = left_virtualspace(H₂, i)
         @assert Vₗ₁[1] == Vₗ₂[1] && Vₗ₁[end] == Vₗ₂[end] "trivial spaces should match"
-        Vₗ = (!isinf && i == 1) ? Vₗ₁ : Vₗ₁[1:(end - 1)] ⊕ Vₗ₂[2:end]
+        Vₗ = (!isinf && i == 1) ? Vₗ₁ : BlockTensorKit.oplus(Vₗ₁[1:(end - 1)], Vₗ₂[2:end])
 
         Vᵣ₁ = right_virtualspace(H₁, i)
         Vᵣ₂ = right_virtualspace(H₂, i)
         @assert Vᵣ₁[1] == Vᵣ₂[1] && Vᵣ₁[end] == Vᵣ₂[end] "trivial spaces should match"
-        Vᵣ = (!isinf && i == length(H)) ? Vᵣ₁ : Vᵣ₁[1:(end - 1)] ⊕ Vᵣ₂[2:end]
+        Vᵣ = (!isinf && i == length(H)) ? Vᵣ₁ :
+             BlockTensorKit.oplus(Vᵣ₁[1:(end - 1)], Vᵣ₂[2:end])
 
         W = similar(eltype(H), Vₗ ⊗ physicalspace(H₁, i) ← physicalspace(H₁, i) ⊗ Vᵣ')
         #=