Improvements

Author: penelopeysm

usage/submodels/index.qmd

@@ -265,6 +265,19 @@ In the case of the `family_model`, we do not care about its return value because
 Ideally, we should therefore not need to place anything on the left-hand side of `to_submodel`.
 However, because the special behaviour of `to_submodel` relies on the tilde operator, and the tilde operator requires a left-hand side, we have to use a dummy variable (here `_n`).
 
+Furthermore, because the left-hand side of a tilde-statement must be a valid variable name, we cannot use destructuring syntax on the left-hand side of `to_submodel`, even if the return value is a NamedTuple.
+Thus, for example, the following is not allowed:
+
+```julia
+(; c0, c1, mu) ~ to_submodel(priors(x))
+```
+
+To use destructuring syntax, you would have to add a separate line:
+
+```julia
+ps = to_submodel(priors(x))
+(; c0, c1, mu) = ps
+```
 
 ## Submodels versus distributions