1fn assignment_value(node: &Assignment) -> &Expr {
2    match node {
3        Assignment::Simple(SimpleBinding::Global(node)) => &node.value
4        Assignment::Simple(SimpleBinding::Local(node)) => &node.value,
5        Assignment::Parallel(ParallelAssignment::Global(node)) => &nod
6        Assignment::Parallel(ParallelAssignment::Local(node)) => &node
7        Assignment::Evaluated(EvaluatedAssignment { value, .. }) => va
8        Assignment::Augmented(node) => &node.value,
9        Assignment::Install(Installation::Method(node)) => &node.funct
10        Assignment::Install(Installation::Op(node)) => &node.function,
11        Assignment::Install(Installation::New(node)) => &node.function
12        Assignment::Op(OperatorAssignment { value_expr, .. }) => value
13    }
14}
15
16impl<Knowledge: PositionedTypeKnowledge + ?Sized> TypeChecker<'_, '_, 
17    pub fn inferred_external_type(
18        &self,