set.seed(123)
    x <- rnorm(100)
    y = 4 + (1.5*x) + rnorm(100, sd = 2)
    DF <- data.frame(x = x,
                     y = 4 + (1.5*x) + rnorm(100, sd = 2),
                     b = as.factor(round(abs(x/3))),
                     c = as.factor(round(abs(y/3)))
    )


m1 <- lm(y ~ b*c, data = DF)