17/10/29 22:16:10.95 LlbU36d2.net
# クラインの4元群Vが正6面体群S(P6)の正規部分群であることの確認
equal <- function(x,y) sum((x-y)^2)==0
tikan2 <- function(X,Y){ # replace Y first then X
n=length(X)
Z=rep(NA,n)
I=1:n
for(i in 1:n){
j <- which(I==X[i])
Z[i] <- Y[j]
}
return(Z)
}
f2 <- function(x,L=G){
re=NULL
for(i in 1:length(L)){
if(equal(L[[i]],x)) return(i) # i for names[i]
}
}
a =c(2,1,4,3)
b =c(3,4,1,2)
c =c(4,3,2,1)
e =c(1,2,3,4)
d =c(1,3,4,2)
t =c(1,2,4,3)
d2 =tikan2(d,d) # 1 4 2 3 # d3=tikan2(d2,d) == e
td =tikan2(t,d) # 1 3 2 4
td2=tikan2(td,d)