OpenLLM-France/wikimedia huggingface dataset:
# Genealogy/Archiving

It is of vital importance that your original photographs, letters, maps, documents and other artifacts are stored properly, with primary attention paid to the preservation of these things. An archiving policy must meet two key requirements: the archives must ensure the long-term physical preservation of the archives, and it also needs to facilitate access to the archives; at times, these two factors can be in opposition.
In this chapter, you can read more about how to preserve and catalogue your:
* photographs; and
* paper documents.

## Notes to be added to this page

* Accessioning: sequential/serial (former implies no gaps in numbering) accession numbers given to all artifacts (photos, documents, etc.), with no duplicates.
* Don't fold or roll anything.
* Accession things, in any order, and store correctly; then catalogue and re-order (most commonly chronologically—which is why there's no need to try and order at accessioning time).
# Electronics Handbook/Components/Oscillator
## Sin Wave Oscillator

The circuit configuration of a Sin Wave Oscillation is made from connecting two components L and C in series
    $L{\frac {dI}{dt}}+{\frac {1}{C}}Idt=0$
    ${\frac {d^{2}I}{dt^{2}}}+{\frac {L}{C}}=0$
    $S^{2}+{\frac {1}{LC}}=0$
    $S=\pm j{\sqrt {\frac {1}{LC}}}=0$
    $I=e^{j\omega t)+e^{-j\omega t)$
    $I=ASin\omega t$
    $\omega ={\sqrt {\frac {1}{LC}}}$

## Standing Wave Oscillator

The circuit configuration of a Sin Wave Oscillation is made from connecting two components L and C in series operating at resonance
    $Z_{L}-Z_{C}=0$
    $V_{L}+Z_{C}=0$
Circuit has the capability to generate Standing Wave oscillating at
    $\omega ={\sqrt {\frac {1}{LC}}}$

## Sin Wave with Decresing Amplitude Oscillator

The circuit configuration of a Sin Wave Oscillation is made from connecting two components L and C in series
    $L{\frac {dI}{dt}}+{\frac {1}{C}}Idt+IR=0$
    ${\frac {d^{2}I}{dt^{2}}}+{\frac {R}{L}}{\frac {dI}{dt}}+{\frac {1}{LC}}=0$
    $S^{2}+{\frac {R}{L}}S+{\frac {1}{LC}}=0$
    $S=-\alpha \pm \lambda =0$
    $\alpha =-{\frac {R}{2L}}$
    $\beta ={\frac {1}{LC}}$
    $\lambda ={\sqrt {\alpha ^{2}-\beta ^{2}}}$
When $\alpha ^{2}<\beta ^{2}$
    $I=e^{-\alpha t)[e^{j\omega t)+e^{-j\omega t)]$
The circuit has the ability to generate Sin Wave with decreasing amplitude
# Electronics Handbook/Components/RC Network
## RC Series

Circuit of R and C connected in series

## Differential Equation of the circuit

At Equilibrium the total voltage is zero
    $V_{C}+V_{R}=0$
    $C{\frac {dV}{dt}}+{\frac {V}{R}}=0$
    ${\frac {dV}{dt}}=-{\frac {1}{RC}}V$
    ${\frac {1}{V}}dV=-{\frac {1}{RC}}dt$
    $\int {\frac {1}{V}}dV=-\int {\frac {1}{RC}}dt$
    ln V = $-{\frac {1}{RC}}+C$
    $V=e^{-}({\frac {1}{RC}})t+C$
    $V=Ae^{-}({\frac {t}{T}})$
With
    T = RC
    A = e$^c$

## Circuit Impedance

    $Z=Z_{R}+Z_{C}$
    $Z=R+{\frac {1}{j\omega C}}$
    $Z={\frac {1}{j\omega C}}(1+j\omega T)$
    T = RC

## Summary

| Circuit | Series RC |
| Configuration | |
| Impedance | $Z=R+j\omega C$ $Z={\frac {1}{j\omega C}}(1+j\omega T)$ |
| T | $T=RC$ |
| Differential Equation | $C{\frac {dV}{dt}}+{\frac {V}{R}}=0$ |
| General Form of Differential Equation | ${\frac {dI}{dt}}+{\frac {1}{T}}=0$ |
| Natural Response | $V(t)=Ae^{-{\frac {t}{T}})$ |
| A | $A=IR$ |
# Electronics Handbook/Components/Regulator
## Zener Diode

A 2 port configuration of a Resistor in series and a Zener Diode in parallel provides the regulated Voltage at a Constant Voltage equal to the Zener Diode's Voltage
# Electronics Handbook/Components/Op Amp Network

    Circuit${\frac {V_{o}}{V_{i}}}$Function Inverting amplifier$V_{\mathrm {out} }=-V_{\mathrm {in} }\left({R_{f} \over R_{1}}\right)$Inverting Amplifier Non-inverting amplifier$V_{\mathrm {out} }=V_{\mathrm {in} }\left(1+{R_{2} \over R_{1}}\right)$Non Inverting Amplifier Voltage follower$V_{\mathrm {out} }=V_{\mathrm {in} }\!\$Voltage Follower Summing amplifier$V_{\mathrm {out} }=-R_{\mathrm {f} }\left({V_{1} \over R_{1}}+{V_{2} \over R_{2}}+\cdots +{V_{n} \over R_{n}}\right)$Voltage Adder Integrating amplifier$V_{\mathrm {out} }=\int _{0}^{t}-{V_{\mathrm {in} } \over RC}\,dt+V_{\mathrm {initial} }$Integrator Differentiating amplifier$V_{\mathrm {out} }=-RC\left({dV_{\mathrm {in} } \over dt}\right)$Differentiator Schmitt triggerHysteresis from ${\frac {-R_{1}}{R_{2}}}V_{sat}$ to ${\frac {R_{1}}{R_{2}}}V_{sat}$schmitt trigger Inductance gyratorL = R$_L$RCGyrator Negative impedance converter$R_{\mathrm {in} }=-R_{3}{\frac {R_{1}}{R_{2}}}$Negative Impedance Converter Logarithmic configuration$v_{\mathrm {out} }=-V_{\gamma }\ln \left({\frac {v_{\mathrm {in} }}{I_{\mathrm {S} }\cdot R}}\right)$Logarithmic Exponential configuration$v_{\mathrm {out} }=-RI_{\mathrm {S} }e^{v_{\mathrm {in} } \over V_{\gamma }}$Exponential
# Electronics Handbook/Components/RL Network
## Series RL

Circuit of R and L connected in series

## Differential Equation of the circuit

At equilibrium the total voltage is zero
    $V_{L}+V_{R}=0$
    $L{\frac {dI}{dt}}+IR=0$
    ${\frac {dI}{dt}}=-I{\frac {R}{L}}$
    $\int {\frac {1}{I}}dI=-\int {\frac {L}{R}}dt$
    ln I = $(-{\frac {L}{R}}t+c)$
    I = $Ae^{-}{\frac {t}{T}}$
Với
    $T={\frac {L}{R}}$
    A = e$^c$
The natural response of the circuit is Exponential Response

## Circuit Impedance

    $Z=Z_{R}+Z_{L}$
    $Z=R+j\omega L$
    $Z={\frac {1}{R}}(1+j\omega T)$
    $T={\frac {L}{R}}$

## Summary

| Circuit | Series RC |
| Configuration | |
| Impedance | $Z=R+j\omega L$ $Z={\frac {1}{R}}(1+j\omega T)$ |
| T | $T={\frac {L}{R}}$ |
| Differential Equation | $L{\frac {dI}{dt}}+IR=0$ |
| General Form ofDifferantial Equation | ${\frac {dI}{dt}}+{\frac {1}{T}}=0$ |
| Natural Response of the circuit | $I(t)=Ae^{-}({\frac {t}{T}})$ |
| A | $A={\frac {V}{R}}$ |
# Electronics Handbook/Components/Microphone
## Microphone

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal

## Reference

* Microphone
# Electronics Handbook/Components/Resistor Network

| Circuit | Derivation | ${\frac {v_{o}}{v_{i}}}$ | Analysis |
| Voltage Divider | ${\frac {V_{o}}{R_{2}}}={\frac {V_{i}}{R_{1}+R_{2}}}$ | ${\frac {v_{o}}{v_{i}}}={\frac {R_{2}}{R_{2}+R_{1}}}$ | R$_2$ = 0 V$_o$ = 0 R$_2$ >> R$_2$ V$_o$ = 1 This configuration is ude maily to attenuate voltage |
| π | ${\frac {V_{i}}{R_{1}}}={\frac {V_{i}-V_{o}}{R_{2}}}+{\frac {V_{o}}{R_{3}}}$ $V_{i}({\frac {1}{R_{1}}}-{\frac {1}{R_{2}}})=V_{o}({\frac {1}{R_{3}}}-{\frac {1}{R_{2}}})$ | ${\frac {v_{o}}{v_{i}}}=({\frac {R_{3}}{R_{1}}})({\frac {R_{2}-R_{1}}{R_{2}-R_{3}}})$ | |
| T | $V={\frac {R_{3}-R_{1}}{R_{2}}}V_{1}={\frac {R_{2}-R_{1}}{R_{2}}}V_{2}$ | ${\frac {V_{2}}{V_{1}}}={\frac {R_{1}+R_{3}}{R_{2}+R_{3}}}$ | |
* ${\frac {V_{o}}{V_{i}}}$
* $R_{eq}=R_{1}+R_{2}+R_{3}+...+R_{n}\,$
* ${\frac {1}{R_{eq}}}={\frac {1}{R_{1}}}+{\frac {1}{R_{2}}}+...+{\frac {1}{R_{n}}}\,$
* $R_{EQ}=(R_{1}\|R_{2})+R_{3}={R_{1}R_{2} \over R_{1}+R_{2}}+R_{3}$
* ${\frac {V_{o}}{V_{i}}}={\frac {R_{2}}{R_{2}+R_{1}}}$
* ${\frac {V_{2}}{V_{1}}}={\frac {R_{2}+R_{3}}{R_{1}+R_{3}}}$
* ${\frac {v_{i}}{v_{o}}}=({\frac {R_{3}}{R_{1}}})({\frac {R_{2}-R_{1}}{R_{2}-R_{3}}})$
* $R_{1}={\frac {R_{\mathrm {a} }R_{\mathrm {b} }}{R_{\mathrm {a} }+R_{\mathrm {b} }+R_{\mathrm {c} }}}$ $R_{2}={\frac {R_{\mathrm {b} }R_{\mathrm {c} }}{R_{\mathrm {a} }+R_{\mathrm {b} }+R_{\mathrm {c} }}}$ $R_{3}={\frac {R_{\mathrm {c} }R_{\mathrm {a} }}{R_{\mathrm {a} }+R_{\mathrm {b} }+R_{\mathrm {c} }}}$
* $R_{\mathrm {a} }={\frac {R_{1}R_{2}+R_{2}R_{3}+R_{3}R_{1}}{R_{2}}}$ $R_{\mathrm {b} }={\frac {R_{1}R_{2}+R_{2}R_{3}+R_{3}R_{1}}{R_{3}}}$ $R_{\mathrm {c} }={\frac {R_{1}R_{2}+R_{2}R_{3}+R_{3}R_{1}}{R_{1}}}$</math>
# Electronics Handbook/Components/LC Network
## LC Series

Circuit of L and C connected in series

## Circuit Analysis
### Circuit Impedance

    $Z=Z_{C}+Z_{L}$
    $Z={\frac {1}{j\omega C}}+j\omega L$
    $Z={\frac {1}{j\omega C}}(j\omega ^{2}+{\frac {1}{T}})$
    T = LC

### Circuit Natural Response

At equilibrium the total voltage of the circuit is zero
    $V_{L}+V_{C}=0$
    $L{\frac {dI}{dt}}+{\frac {1}{C}}\int Idt=0$
    ${\frac {dI}{dt}}+{\frac {1}{LC}}\int Idt=0$
    ${\frac {d^{2}I}{dt^{2}}}+{\frac {1}{LC}}=0$
    $s^{2}=-{\frac {1}{LC}}$
    s = ± ${\sqrt {-{\frac {1}{LC}}}}$ = ± j ${\sqrt {\frac {1}{LC}}}$
    $I=e^{j{\sqrt {\frac {1}{LC}}}t)+e^{-j{\sqrt {\frac {1}{LC}}}t)$
    $I=ASin{\sqrt {\frac {1}{LC}}}t$
    $I=ASin\omega t$
At equilibrium or The natural response of the LC series is the Sinusoidal Wave Oscillation

### Resonance

Resonance occurs when the frequency components cancel each other out . Therefore, at resonance
    $Z_{L}=Z_{C}$
    $\omega L={\frac {1}{\omega C}}$
    $\omega ={\sqrt {\frac {1}{LC}}}$
    $V_{C}=-V_{L}$
At resonance the response of the LC series is the Standing Wave Oscillation

## Summary

* The natural frequency reponse of the circuit is a Sinusoidal Wave
* At resonance, the frequency reponse of the LC series is the oscillation of a Standing Wave
| Circuit | Series LC |
| Configuration | |
| Impedance | $Z={\frac {1}{j\omega C}}(j\omega ^{2}+{\frac {1}{T}})$ |
| Differential Equation | $L{\frac {dI}{dt}}+{\frac {1}{C}}\int vdt=0$ |
| General Differential Equation | ${\frac {d^{2}I}{dt}}+{\frac {1}{T}}=0$ |
| Natural Response | $I(t)=e^{j\omega t)+e^{-j\omega t)$ $I(t)=ASin\omega t$ |
| T | $T=LC$ |
| $\omega$ | $\omega ={\sqrt {\frac {1}{T}}}$ |
| A | $A={\frac {1}{2j}}$ |
# Grand Theft Auto: San Andreas/Missions/Deconstruction
## Prerequisites

* Mission: Wear Flowers in your Hair
* Location: CJ's garage, Doherty, San Fierro

## Walkthrough

After the cutscene, you have three minutes to use the Dozer to destroy the portables. Watch out for the explosive barrels. After this, you must use the Dozer to push mobile toilet containing the foreman into a hole (besides the pipes), and cover it with concrete.

## Tips

* If the other Dozer bothers you too much, get off your Dozer and shoot him. The other workers won't use that again. Don't bother killing other workers though as they will keep on spawning.

## Rewards

None

## New Missions Available

* Photo Opportunity
* Back to School
# Grand Theft Auto: San Andreas/Missions/Doberman
## Prerequisites

* Mission: Cesar Vialpando
* Mission: Burning Desire
* Location: Ammu-Nation, Market, Los Santos

## Walkthrough

This mission will introduce you to Gang Wars. First go to Ammunation and strap up with armor and everything for war. Then head over to Glen Park and start a gang war by killing 3 or more Ballas, the ones in groups. A turf war is now started, then 3 waves of Ballas will come and you must kill them all. After that, the snitch (Doberman) will appear and you just have to kill him.

## Rewards

* Respect: +40
* Ammunation now open
* Turf Wars available (Note: You lose all territories after The Green Sabre)
* CJ's house becomes an asset

## New Missions Available

* Los Sepulcros (also requires: 10% Total Respect)
# Grand Theft Auto: San Andreas/Missions/Cut Throat Business
## Prerequisites

* Mission: Home Coming
* Location: Madd Dogg's Crib, Los Santos

## Walkthrough

This is a pretty easy mission. First, go to the destination marked with Mad Dogg. There is a BF Injection outside if you want to take it. Then you will be in a Vortex. Just follow OG Loc and forget about Madd Dogg. Eventually you'll get in a go-kart and the chase will continue until you end up at OG Loc's record company.

## Tips

* Don't try to drive-by Loc. You can't catch up to him and he is invincible.
* For the PC version: If your framerate is below nominal, you may find it nearly impossible to keep up with Loc. (A lower framerate will slow down your own movement, but not Loc's.) To circumvent this problem, use the mouse to continually force the camera into a top-down view, which will improve your framerate. Use the radar to steer by, and "look up" only as often as is needed to dodge obstacles that do not show on the radar.

## Rewards

* Respect+

## New Missions Available

None
# Grand Theft Auto: San Andreas/Missions/Don Peyote
## Prerequisites

* Mission: You've had your Chips
* Location: Four Dragon's Casino, Las Venturas

## Walkthrough

This mission actually starts outside the casino, the red mission marker is on the red carpet and can be hard to see if you are running around the corner from the last mission, it caught me out anyway. Your cell-phone will ring, it's the Truth, it seems that he has two friends lost in the desert and it's up to you to go and find them.
Once you reach the location and find Paul and Maccer you need to get your vehicle close enough to them to trigger them to get inside, they are not too hot at following on foot so be careful as a wrecked or overturned vehicle could result in fatalities and therefore mission failure as they will clamber out but probably not run away. Anyway, it seems that one of them can remember "lots of snakes" and CJ knows there is a Snake Farm somewhere locally (it's actually on the corner of the Verdant Meadows Airstrip) so that's where you head next. When you arrive, the locals aren't too pleased to see Paul and Maccer again so you have to head off rapidly towards Las Venturas with a couple of Walton Pickups in hot pursuit.
En-route to Las Venturas one of the dynamic duo recalls a casino name and that's where you head to, on arrival a cutscene shows the party entering the building to visit someone inside before you depart to complete the mission. Later you will get a call on your cell-phone from Paul to offer you work.
* As hot as these seemingly Steam-propelled vehicles can muster anyway!

### Funny Moments

* When you're driving to the Snake Farm with Paul and Maccer, take note that if you pull over when Paul is about to vomit, he will get out of the car and hurl on the ground. If you didn't stop, he'll vomit right in the car.
* In about 30 seconds after Paul's hurl, Maccer will say he wants to use the bathroom. If you pulled over, he will get out of the car and you'll see how he will pee right on the ground (genitals not explicitly shown).

## Tips

You are collecting two people so it helps if you have a car with four doors, also bear in mind they are lost in the desert so an off-roader would be handy, Landstalker anyone?
If possible, shoot the rednecks before running to the car, thus giving you a free run back without any pursuit.
Make use of the space at Verdant Meadows to deal with the pickups before heading back to Las Venturas, if you are suitably tooled-up you can dispose of them relatively easily, no point in making the return journey any more difficult than is absolutely necessary.
Alternatively, a Maverick helicopter works great for this mission since it has 4 doors.

## Rewards

* Respect+

## New Missions Available

* Intensive Care
# Grand Theft Auto: San Andreas/Missions/Drive-By
## Prerequisites

* Mission: Nines and AK's
* Location: Sweet's house, Grove Street, Ganton, Los Santos

## Walkthrough

After the cutscene get into Sweet's Greenwood car, and drive to the red marker in Jefferson. Be careful with the car. If it should be destroyed, you fail the mission.
Drive by the Ballas and let the Grove do the work. If you have an SMG, you can join in if you like, but be careful and watch out for your car's health. Repeat this with three more groups of Ballas. By the time you reach the last group, found in Glen Park, usually your car is almost destroyed, so just run over the Ballas (which you could've done from the very start). You'll get two stars, but it doesn't matter, just go to the nearest Pay N Spray.
After this, drive back to Sweet's house to complete the mission.
If you find it too difficult to do this way, you can stop the car just out of range of a group of Ballas, and snipe them from a distance. Don't stray too far from the car, or you will fail the mission.

## Rewards

* Cash: $500
* Respect: +6

## New Missions Available

* Sweet's Girl
* Home Invasion
# Grand Theft Auto: San Andreas/Missions/Dam and Blast
## Prerequisites

* Mission: Key to her Heart
* Location: Four Dragons Casino, Las Venturas

## Walkthrough

Go to the airport, fly to the dam, and then parachute out. Your plane needs to go through a red corona in the sky before it lets you jump out. After you have landed near the dam, all your weapons will be removed. Pick up the knife near the containers and try to stealth kill the two guards. Get in the building, plant explosives on all the generators. Kill the mechanics and guards if you have to. Despite the warning that the whole warehouse will be notified of your presence only one of the mechanics has a gun. CJ will dive from the roof of the building into the water. Steal the skimmer plane or the sea sparrow and go where you need to.

## Tips

The corona is very high in the air so once you take off, fly south and get some distance for you to climb up before turning around.
If you land in the red marker after the parachute jump you'll keep all your weapons.

## Rewards

None

## New Missions Available

* Cop Wheels
# Grand Theft Auto: San Andreas/Missions/Cop Wheels
## Prerequisites

* Mission: Dam and Blast
* Location: Four Dragons Casino, Las Venturas

## Walkthrough

You have to steal four police motorcycles (specific ones not just any old one) and load them on a truck driving around the Las Venturas freeway within 12 minutes.
You will get a two-star wanted level during this mission, you can either live with the Police attention or look for bribes, time is tight and there isn't really time for Pay n Spray visits although if you are passing one and have plenty of time it wouldn't hurt to drop in.
Once you have your first bike, the truck is indicated by a blue blip on the radar, ride to the location (it circles the thruway clockwise) and ride it up the ramp Italian Job style.
After delivering each bike to the truck you will need to decide whether to ride with the truck to an exit off the freeway closer to the bike or immediately run off the truck and get a new vehicle. Personally I'd go with the new vehicle option as you can get going much faster but in some circumstances you may find yourself in easy reach of the next bike.
Once all four bikes are loaded on the truck there is a short cutscene before the mission ends and you are dropped at Whitewood Estates.

## Tips

If you haven't started using the map menu and the map marker yet, learn how to do so now. Every turn should be pre-planned, as taking extra turns can cost a lot of time.
The bikes are always at specific locations and it is easier to tackle them in a clockwise direction as this follows the direction of the truck. The locations and the best order is given below:
* Linden Station turn off on the freeway
* The Hospital car park (the bike will ride away as soon as you arrive)
* Outside the Police Station
* Entrance to the Rock Motel (bike will start chasing a group of bikers when you arrive)
Don't try to shoot police officers off the bikes - a bike will explode if hit once, failing the mission. It's best to disable officers by running over them with your vehicle, preferably before they can get to their bike.

## Rewards

* Respect +

## New Missions Available

* Up, Up and Away!
# Grand Theft Auto: San Andreas/Missions/Customs Fast Track
## Prerequisites

* Mission: Test Drive
* Location: CJ's garage, Doherty, San Fierro

## Walkthrough

This is your introduction to the Import/Export Crane of San Andreas. Begin by heading to the docks and get into the crane. Moving the crane by using the left analog stick and use the X and Square buttons to control height of the electromagnet. When you have the magnet above the crate, press O to latch the crate onto the magnet and move it off of the container ship. Repeat this process until you find the crate with the target car in it. Exit the crane and you will see a cutscene with 6 guys who's determined to stop your thievery, waste them and return the car to the garage.
The amount of cash you receive will depend on the amount of damage dealt to the car before you return it.

## Rewards

* Cash: Up to $10,000 (see above)
* Respect: +5
* Import/export crane opens

## New Missions Available

* Puncture Wounds
# Grand Theft Auto: San Andreas/Missions/Drive-thru
## Prerequisites

* Mission: Cleaning the Hood
* Location: Sweet's house, Grove Street, Ganton, Los Santos

## Walkthrough

Smoke's hungry, so the Grove decides to head out to get some food. After the cutscene, drive to the Cluckin' Bell, and into the red marker to trigger the next cutscene, which truly demonstrates the extent of Smoke's gluttony. After this, Ryder scopes out a Balla ride, and sees that they're planning a hit.
If the Balla car makes it back to Grove Street, you fail the mission, so quickly smash the Balla car into a wall and let your people do the work. They have such bad aiming, it almost seems as if the Balla car is bulletproof. However, if you have an SMG, Micro-SMG or Tec9, you can help them out by performing a drive-by. Eventually, the car will be on fire, and you can watch the Ballas die when the car explodes. If they haven't died, hop out your car and blast on fools, or just run them down.
Once the Ballas are all dead, drive back to Sweet's house, and then on to Smoke's house to complete the mission.

## Rewards

* Cash: $200
* Respect: +5
* Los Santos Gym opens.

## New Missions Available

* Nines and AK's
# Four-Player Chess/Checkmate patterns

All checkmate patterns that occur in regular chess can also occur in four-player chess. In four-player chess, however, players can combine forces to checkmate another player without that player being able to intervene, as he will have to wait for his turn. This makes for some interesting checkmates that are described in this section.

## Fool's mate

The fastest mate in the Teams variant takes only two moves. If Red and Yellow both open on the dark squares with h3 (or h4) and g12 (or g11), respectively, and Green also opens up the dark squared diagonals with l7 (or k7), then Green gets mated, if Blue does not intervene. Red plays Qxn8+ and Yellow supports the queen with Bm7#. This mate can easily be avoided, if Blue keeps a check on Yellow in hand.

## Scholar's mate

This is a three-move mate in the Teams variant. Red opens with h3 (or h4), Yellow plays h11 and Green plays l7 (or k7). Then Red captures on n8 and Yellow plays Qh12. Green is in check and has to recapture the queen, but then Yellow mates with Qxn6#, if Blue does not intervene. Just like Fool's mate, this mate can easily be avoided, if Blue keeps a check on Yellow in hand. It can be in other forms, but still with yellow queen on n6, green king on n8 and green figures on m8, m9 and n9.

## Two queens double check mate

This is the most basic type of checkmate in four-player chess. The queens of two players both check an opponent's king while supporting each other.

## Queen and knight double check mate

This is another common checkmate, in which the queen and knight both check the opponent's King while the knight supports the Queen.