warn that multiplication and derivative may fail...

CHANGELOG.md

@@ -16,4 +16,4 @@ parameters, and default processes.
 - New keyword `warn_default` in `processes_to_mtkmodel`.
 - Now `processes_to_mtkmodel` allows for `XDESystems` as elements of the input vector.
 - Detection of LHS-variable in `Equation` has been improved significantly.
-  Now, LHS can be any of: `x`, `Differential(t)(x)`, `Differential(t)(x)*p`, `p*Differential(t)(x)`.
+  Now, LHS can be any of: `x`, `Differential(t)(x)`, `Differential(t)(x)*p`, `p*Differential(t)(x)`. However, the multiplication versions often fail for unknown reasons.

src/make.jl

@@ -11,7 +11,8 @@ The model/system is _not_ structurally simplified.
    or not having limitations on the left-hand-side (LHS) form.
 1. An `Equation`. The LHS format of the equation is limited.
    Let `x` be a `@variable` and `p` be a `@parameter`. Then, the LHS can only be one of:
-   `x`, `Differential(t)(x)`, `Differential(t)(x)*p`, `p*Differential(t)(x)`.
+   `x`, `Differential(t)(x)`, `Differential(t)(x)*p`, `p*Differential(t)(x)`,
+   however, the versions with `p` may fail unexpectedly.
    Anything else will either error or fail unexpectedly.
 2. A vector of the above two, which is then expanded. This allows the convenience of
    functions representing a physical process that may require many equations to be defined.