List of boolean not evaluated correctly

[hugohills-regnosys]

type Foo:
    attr boolean (1..1)

func ShouldEvalulateToSingleCardinality:
    inputs:
        foos Foo (0..*)
    output:
        result boolean (0..1)

    set result:
        foos extract ExtractAttr // should cause validation error because this returns a list of booleans rather than a single

func ExtractAttr:
    inputs:
        foo Foo (1..1)
    output:
        extractedAttr boolean (1..1)

    set extractedAttr:
        foo -> attr

The above function ShouldEvalulateToSingleCardinality should cause a validation error because the list of booleans needs to reduced to a single boolean, for example by add then all = True.