```uclid
module main {
    type Side;
    const left: Side;
    const right: Side;

    // Variables representing locations
    var ferryman : Side;
    var goat : Side;
    var cabbage : Side;
    var wolf : Side;
    var carry : Side;

    // Initial state
    init
    {
        ferryman = left;
        goat = left;
        cabbage = left;
        wolf = left;
        carry = left;
    }

    // Transition relation
    next
    {
        ferryman' = carry;
        if (carry = wolf) {
            wolf' = carry;
        } else {
            wolf' = wolf;
        }

        if (carry = goat) {
            goat' = carry;
        } else {
            goat' = goat;
        }

        if (carry = cabbage) {
            cabbage' = carry;
        } else {
            cabbage' = cabbage;
        }

        carry' = if (carry = left) then right else left;
    }

    // Safety condition: goat and cabbage or goat and wolf must not be alone
    constraint
    {
        (goat = cabbage => ferryman = goat) && (goat = wolf => ferryman = goat);
    }

    // Goal state
    define goalState : bool {
        ferryman = right && goat = right && cabbage = right && wolf = right;
    }

    // Reachability property: Can we achieve the goal state without violating constraints?
    control {
        check;
    }
    synth invariant;
}
```
This UCLID5 code models the classic river crossing problem, where the ferryman needs to take a wolf, a goat, and a cabbage across the river. It ensures the safe transport across the river without any conflict among the characters when left alone on one side. The model checks the property whether the goal state, where everyone has crossed to the right side of the river, is reachable under the specified constraints.