*求孪生素数的15对
DIMENSION ssd[15,2]
CLEAR
n=1
FOR i=3 TO 1000 SKIP 2
IF ispn(i) .and. ispn(i+2)
ssd[n,1]=i
ssd[n,2]=i+2
?'第'+LTRIM(STR(n))+'对孪生素数:',ssd[n,1],ssd[n,2]
n=n+1
IF n>15
EXIT
ENDIF
ENDIF
ENDFOR
RETURN
FUNCTION ispn
PARAMETERS sz
IF sz<2
RETURN .f.
ENDIF
ssbz=.t.
FOR j1=2 TO (sz-1)/2
IF MOD(sz,j1)=0
ssbz=.f.
EXIT
ENDIF
ENDFOR
RETURN ssbz