Set constraint if qval is not a number

src/components/instant_gradients.jl

@@ -25,7 +25,7 @@ function (::Type{InstantGradient})(; orientation=nothing, group=nothing, qval=no
         res = InstantGradient3D(get_free_variable.(qval), group)
     else
         res = InstantGradient1D(get_free_variable(qval), orientation, group)
-        if res.qval isa Number
+        if !(res.qval isa Number)
             @constraint global_model() res.qval >= 0
         end
     end