Example: ** Home Theatre - Plugging a variety of components with different connections together to watch a DVD.

    "Home Theatre" by Sean Turner

    Include Plugs and Sockets by Sean Turner

    Section 1 - New plug and socket kinds

    An HDMI-plug is a kind of PS-plug. The type of an HDMI-plug is "HDMI".
    An HDMI-socket is a kind of PS-socket. The type of an HDMI-socket is "HDMI".

    A DVI-plug is a kind of PS-plug. The type of a DVI-plug is "DVI".
    A DVI-socket is a kind of PS-socket. The type of a DVI-socket is "DVI".

    A power-plug is a kind of PS-plug. The type of a power-plug is "power". A power-plug has a truth state called searched state. The searched state of a power-plug is usually false.

    A power-socket is a kind of PS-socket. The type of a power-socket is "power".

    A double-adapter is a kind of thing. Every double-adapter incorporates a power-plug and two power-sockets.

    A hifi-gadget is a kind of thing. Every hifi-gadget incorporates a power-plug.

    Section 2 - A few decisions

    To decide if the (test-item - a thing) is powered:
        repeat with item running through the power-plugs:
            now the searched state of the item is false;
        let forever be true;
        while forever is true:
            if the test-item is the power point:
                decide yes;
            let test-plug be a random power-plug which is part of the test-item;
            if the test-plug is nothing, or the attachment of the test-plug is nothing:
                decide no;
            else:
                if the searched state of the test-plug is true:
                    decide no;
                now the searched state of the test-plug is true;
                now the test-item is the holder of the attachment of the test-plug.

    To decide if the audio is connected:
        if the HDMI cable is inserted into the receiver, and the HDMI cable is inserted into the DVD player, and the holder of the attachment of the HDMI-IN socket is HDMI cable:
            decide on true;
        decide on false.

    To decide if the video is connected:
        if the video converter is inserted into the TV, and the video converter is inserted into the receiver, and the attachment of the HDMI-OUT socket is the green plug:
            decide on true;
        decide on false.

    Section 3 - Scenario

    The Home Theatre is a room. "This softly lit and richly carpeted homage to 1970's decor is the perfect place to relax and watch a movie. A store room is to the south."

    A big screen TV is a hifi-gadget. It is here. "A huge 150cm Plasma TV dominates the north wall.". It is fixed in place.
    The description is "Tastelessly huge. The TV is [if the TV is powered]on although nothing is showing.[else]off.".
    Incorporated by it is a DVI-socket.

    A power point is here. It is fixed in place. "Unfortunately the room has only one single power point tucked away in the corner farthest from the TV."
    Incorporated by it is a power-socket.

    Check plugging a PS-inserter into the power point (this is the power-point-too-far rule):
        if the noun is fixed in place, say "The plug of [the noun] will not reach to [the power point]." instead;
        if the noun is not the extension cord, say "It would be useless to plug [the noun] into [the power point] when it is so far from the TV." instead.

    The power-point-too-far rule is listed last in the check plugging it into rulebook.

    A Blu-ray DVD player is a hifi-gadget. It is here. The description is "A state of the art DVD player. In the player is a movie waiting to be watched. The DVD player is [if the DVD is powered]on and the movie is playing.[else]off."
    Incorporated by it is an HDMI-socket.

    A digital receiver is a hifi-gadget. It is here. It is fixed in place.
    The description is "A complex switching mechanism routing various audio visual inputs to the TV and speakers. The speakers are hard-wired into the back of the receiver. On the back of the receiver are two HDMI sockets labeled HDMI-IN and HDMI-OUT.
    
    The receiver is [if the receiver is powered]on and hums slightly.[else]off.".
    Incorporated by the receiver is an HDMI-socket called the HDMI-OUT socket.
    Incorporated by the receiver is an HDMI-socket called the HDMI-IN socket.

    Some speakers are scenery. They are here.

    The Store room is south of the Home Theatre.

    An extension cord is here. The description is "5 metres of sturdy electrical cord.". The indefinite article is "an".
    Incorporated by it is a power-plug and a power-socket.

    A video converter cable is here. The description is "It converts from an HDMI source to a DVI destination - useful when only the video component of the signal is required. The male DVI plug is red and the male HDMI plug is green.".
    Incorporated by the cable is a DVI-plug called the red plug.
    Incorporated by the cable is an HDMI-plug called the green plug.

    An HDMI cable is here. Incorporated by it are two HDMI-plugs. The indefinite article is "an". The description is "Connects two HDMI devices for video and sound. The two male connectors are indistinguishable.".

    A cream double adapter is a double-adapter. It is here.
    A white double adapter is a double-adapter. It is here.

    Section 4 - Victory condition

    Every turn:
        let power flowing be true;
        repeat with item running through hifi-gadgets:
            unless the item is powered:
                now power flowing is false;
        if power flowing is true, and the audio is connected, and the video is connected:
            say "Ahh. Now you can relax and watch the movie.";
            end the story saying "You have won.";
        else:
            if the receiver is powered, and the DVD is powered, and the audio is connected:
                say "You can hear the movie but you can't see any picture!".


    Section 5 - Testing

    test me with "s/get all/n/plug tv into white/plug dvd into white/plug white into cream/plug receiver into cream/plug cream into cord/plug cord into point/plug hdmi into receiver/plug hdmi into dvd/plug video into receiver/x green/x red/plug video into tv/unplug video from receiver/unplug hdmi from receiver/plug hdmi into hdmi-in/plug video into hdmi-out".

    test errors with "plug tv into point/plug tv into receiver/s/get all/n/plug cord into point/s/plug hdmi into cream/unplug cord from point/plug cord into cord/unplug cord/plug tv into white/plug receiver into white/ plug cream into white/unplug tv/plug red plug into receiver/plug green plug into receiver/plug video cable into tv".