Example of using a definition variable in a RAM model

But can it be extended to the typical case of

x-->y;
def--> y;
x*def-->y

?
i.e., to include the def on the diagram as a manifest, and use it as a definition variable?

# make up some data
require(umx); library(MASS)
N = 500 # sample size, per group
Sigma = matrix(c(1,.5,.5,1),2,2)
group1 = mvrnorm(N, c(1,2), Sigma) # Use mvrnorm from MASS package
group2 = mvrnorm(N, c(0,0), Sigma)

# Put the two groups together, create a definition variable,
# and make a list of which variables are to be analyzed (selVars)
xy = rbind(group1,group2) # Bind groups together by rows
dimnames(xy)[2] = list(c("x","y")) # Add names
def = rep(c(1,0),each=N); # Add def var [2n] for group status
selVars = c("x","y") # Make selection variables object
df = data.frame(xy,def)

#############################################
# Make a model with moderation using a definition variable #
#############################################
m1 = mxModel("def_test", type="RAM", manifestVars= c("x", "y"), latentVars= "dummy", mxData(df, type= "raw"),
mxPath(c("x", "y"), arrows= 2, free= TRUE),
mxPath("one", to = c("x","y"), arrows= 1, free= TRUE),
mxPath("dummy", value= 0, arrows= 2, free= FALSE),
mxPath("one", to = "dummy", value= 0, free= FALSE),
mxPath("x", to = "y"),
mxPath("x", to = "dummy", values=0, free=FALSE, label = "data.def"),
mxPath("dummy", to = "y")
)
m1 = mxRun(m1)