The first formula is "Darvas High" which identifies new period highs followed by three lower highs.

Name of Indicator:  Darvas High

Formula:

Periods:=100; { this is the only place the number of periods is set}

If((Ref(H,-3) >= Ref(HHV(H,Periods),-4))

       AND Ref(H,-3) > Ref(H,-2)

       AND Ref(H,-3) > Ref(H,-1)

       AND Ref(H,-3) > H,

   Ref(H,-3), PREVIOUS );

Name of Indicator:  New Darvas High

Formula:

dh:= Fml("Darvas High");

def:=IsDefined(dh) AND IsDefined(Ref(dh,-2));

(def AND Ref(def,-1)=0) + (dh AND Ref(dh,-1)<>dh);

Name of Indicator:  New Darvas Low

Formula:

dh:= Fml("Darvas High");

ndl:=(Ref(L,-3) < Ref(L,-2) AND Ref(L,-3) < Ref(L,-1)

AND Ref(L,-3) < L AND Ref(H,-2) < dh

AND Ref(H,-1) < dh AND H < dh);

def:=IsDefined(dh) AND IsDefined(Ref(dh,-1));

(def AND Ref(def,-1)=0)+ (ndl AND (Ref(ndl,-1) < 1))

Name of Indicator:  Darvas Low

Formula:

If( Fml("New Darvas Low") , Ref(L,-3),  PREVIOUS);

Name of Indicator:  Darvas Box End

Formula:

end:=BarsSince(Fml("New Darvas High")) <

    BarsSince(Ref(Fml("New Darvas Low"),-1));

def:=IsDefined(end) AND IsUndefined(Ref(end,-1));

(def AND Ref(def,-1)=0)+ (end AND Fml("New Darvas Low"))

We are now in a position to plot the High and Low of the Darvas box.

Name of Indicator:  Darvas Box High

Formula:

dbe:=Fml("Darvas Box End");

dbhi:=If(dbe AND IsDefined(Ref(dbe,-1)),  Fml("Darvas High"), PREVIOUS);

If(dbhi=0,H+0.0000001,dbhi)

Name of Indicator:  Darvas Box Low

Formula:

dbe:=Fml("Darvas Box End");

bl:=If(dbe AND IsDefined(Ref(dbe,-1)),  Fml("Darvas Low"), PREVIOUS);

If(bl=0,L-0.0000001,bl)

Next we need to develop the Sell Indicator.  First we look for possible sell signals.

Name of Indicator:  Darvas Poss Sell

Formula:

dsl:=L < Fml("Darvas Box Low");

def:=IsDefined(dsl) AND IsDefined(Ref(dsl,-1));

(def AND Ref(def,-1)=0)+(dsl AND (Ref(dsl,-1)<dsl))

Name of Indicator:  Darvas Sell

Formula:

sell:=BarsSince(Fml("Darvas Box End")) <

BarsSince(Fml("Darvas Poss Sell"));

def:=IsDefined(sell) AND IsDefined(Ref(sell,-1));

((def AND Ref(def,-1)=0) + (sell = 0 AND Ref(sell,-1)=1))

Name of Indicator:  Darvas Buy

Formula:

dc:= Fml("darvas sell");

{ change the following line to H>Fml("Darvas Box Hi") .. for Classic Darvas}

db:= C>Fml("Darvas Box Hi") AND

           (BarsSince(Fml("darvas box end")) < BarsSince(Fml("darvas sell")));

dto:=If(db AND PREVIOUS=0,1,If(dc,0,PREVIOUS));

dto AND (Ref(dto,-1) =0)

Using these formulas it is simple to create a new Metastock Expert Advisor for Darvas.   Create a New advisor, call it Darvas and fill in the following tabs

For the Trends tab I used the somewhat arbitrary

Bullish    C >=  Fml("Darvas Box Low");

Bearish    C < Fml("Darvas Box Low");

For Symbols tab use

Buy: up arrow graphic, formula  Fml("Darvas Buy")

Sell: down arrow graphic, formula  Fml("Darvas Sell")

For Alerts tab use

Buy: formula  Fml("Darvas Buy") and some suitable text message such as "buy on next open"

Sell: formula  Fml("Darvas Sell") and some suitable text message such as "sell on next open"