idiom119 broken, since moving feature∈ to property.equatable

[michaellilltokiwa]

/home/not_synced/flang_dev/idioms/src/idiom119ex.fz:7:37: error 1: Call has an ambiguous result type since target of the call is a 'ref' type.
         r list String := nil, if e ∈ s then r
------------------------------------^^^
The result type of this call depends on the target type.  Since the target type is a 'ref' type that may represent a number of different actual dynamic types, the result type is not clearly defined.
Called feature: 'property.equatable.infix ∈'
Raw result type: 'container.Set property.this.equatable.this'
Type depending on target: 'property.this.equatable.this'
Target type: 'String'
To solve this, you could try to use a value type as the target type of the call, e,g., 'property.equatable', or change the result type of 'property.equatable.infix ∈' to no longer depend on 'property.this.equatable.this'.

one error.