Deduplicate a list of lm objects in R -

i have list of lm models objects possible repeated, i'd find way of checking if of these lm objects equal, if them delete it. in words, want "deduplicate" list.

i'd appreciate help.

an example of problem:

## creates outcome , predictors outcome    <- c(names(mtcars)[1:3]) predictors <- c(names(mtcars)[4:11]) dataset    <- mtcars  ## creates model list model_list <- lapply(seq_along((predictors)), function(n) {   left_hand_side  <- outcome[1]   right_hand_side <- apply(x = combn(predictors, n), margin = 2, paste, collapse = " + ")   paste(left_hand_side, right_hand_side, sep = "  ~  ") })  ## convert model list verctor model_vector <- unlist(model_list)  ## fit linear models itens vector of models list_of_fit <- lapply(model_vector, function(x) {   formula    <- as.formula(x)   fit        <- step(lm(formula, data = dataset))   fit })  # exclude possible missing list_of_fit <- filter(negate(function(x) is.null(unlist(x))), list_of_fit)  # these models same in list lm253 <- list_of_fit[[253]];lm253 lm254 <- list_of_fit[[254]];lm254 lm255 <- list_of_fit[[255]];lm255 

i want exclude duplicated entries in list_of_fit.

it seems wasteful fit many models , throw away of them. object names make code hard read me, seems models can distinguished based on formula. maybe helps:

lista_de_ajustes[!duplicated(vapply(lista_de_ajustes,                                      function(m) deparse(m$call),                                      fun.value = "a"))]