Non real solvability

[HansOlsson]

According to decision (as far as I can see).
Closes #3779

[henrikt-ma]

Main concern is the lack of relation to switching condition evaluability.

[henrikt-ma]

I also realized that we need to distinguish between simple and non-simple equations:

Suggested change

	Non-\lstinline!Real! equations in the \lstinline!if!-equation branches shall have component-references (or a list of them) as their left-hand-side.
	Non-\lstinline!Real! simple equality equations (see \cref{simple-equality-equations}) in the \lstinline!if!-equation branches shall have component-references (or a list of them) as their left-hand-side.

[HansOlsson]

The "list of them" was for non-simple, so if we only mention simple it would be:

Suggested change

	Non-\lstinline!Real! equations in the \lstinline!if!-equation branches shall have component-references (or a list of them) as their left-hand-side.
	Non-\lstinline!Real! simple equality equations (see \cref{simple-equality-equations}) in the \lstinline!if!-equation branches shall have component-references as their left-hand-side.

[henrikt-ma]

Hmm… this is one of the examples in \cref{simple-equality-equations}:

(out1, out2, out3) = function_name(inexpr1, inexpr2);

What am I missing?

[henrikt-ma]

We also need something for the non-simple equations:

Suggested change

	Any subscripts for such component-references must be evaluable.
	Any subscripts for such component-references must be evaluable.
	Any \lstinline!for!- and \lstinline!if!-equations in the \lstinline!if!-equation branches shall have evaluable controlling conditions, and contain equations which fullfil these requirements recursively.

[HansOlsson]

To me the recursive part worked automatically: for-equations shall always have evaluable conditions, and nested if-equations containing non-Real equations follow from just applying the rule for that if-equation.

[henrikt-ma]

Besides the requirements on these equations, I also wanted to make clear that they may qualify for the matching of branches, despite not being given in simple equality equation form.