const binorm = "
transformed data {
  matrix[2,2] Sigma;
  vector[2] mu;
  mu[1] <- 0.0;
  mu[2] <- 0.0;
  Sigma[1,1] <- 1.0;
  Sigma[2,2] <- 1.0;
  Sigma[1,2] <- 0.10;
  Sigma[2,1] <- 0.10;
}
parameters {
  vector[2] y;
}
model {
    y ~ multi_normal(mu,Sigma);
}
"
