Just for kicks, here's a Dart version:

    enum ItemStatus { notAvailable, available, inUse }

    enum FieldState { hidden, readOnly, readWrite }

    FieldState decide(bool requiresApproval, bool canUserApprove, ItemStatus itemStatus) =>
        switch ((requiresApproval, canUserApprove, itemStatus)) {
          (true,  true,  ItemStatus.notAvailable) => FieldState.hidden,
          (false, true,  ItemStatus.notAvailable) => FieldState.hidden,
          (true,  false, ItemStatus.notAvailable) => FieldState.hidden,
          (false, false, ItemStatus.notAvailable) => FieldState.hidden,
          (true,  true,  ItemStatus.available   ) => FieldState.readWrite,
          (false, true,  ItemStatus.available   ) => FieldState.hidden,
          (true,  false, ItemStatus.available   ) => FieldState.readOnly,
          (false, false, ItemStatus.available   ) => FieldState.hidden,
          (true,  true,  ItemStatus.inUse       ) => FieldState.readOnly,
          (false, true,  ItemStatus.inUse       ) => FieldState.hidden,
          (true,  false, ItemStatus.inUse       ) => FieldState.readOnly,
          (false, false, ItemStatus.inUse       ) => FieldState.hidden,
        };

As with F# and Haskell, the compiler will tell you if you didn't cover one of the combinations. In the case of Dart, we go ahead and make it a full compile-time error, not just a warning.

The cool thing about pattern matching over tuples with compile-time exhaustiveness checking is that you can start simplifying and collapsing rows and the compiler will let you know if you made a mistake.

I believe you can simplify the example here to:

    FieldState decide(bool requiresApproval, bool canUserApprove, ItemStatus itemStatus) =>
        switch ((requiresApproval, canUserApprove, itemStatus)) {
          (_,         _, ItemStatus.notAvailable) => FieldState.hidden,
          (false,     _, ItemStatus.available   ) => FieldState.hidden,
          (false,     _, ItemStatus.inUse       ) => FieldState.hidden,
          (true,  false, ItemStatus.available   ) => FieldState.readOnly,
          (true,      _, ItemStatus.inUse       ) => FieldState.readOnly,
          (true,   true, ItemStatus.available   ) => FieldState.readWrite,
        };

Doing that simplification is a useful exercise to then determine how to express the rules you're modeling in a succinct way.