diff --git a/.gitignore b/.gitignore
index df3fb06..0fc1327 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,3 +33,4 @@ node_modules/
 # https://github.com/thelmuth/program-synthesis-benchmark-datasets
 /data
 **/.DS_Store
+.shadow-cljs/classpath.edn
diff --git a/src/propeller/gp.cljc b/src/propeller/gp.cljc
index 7c87229..3c89f00 100644
--- a/src/propeller/gp.cljc
+++ b/src/propeller/gp.cljc
@@ -61,7 +61,7 @@
             (prn {:total-test-error
                   (:total-error (error-function argmap (:testing-data argmap) best-individual))})
             (if (:simplification? argmap)
-              (let [simplified-plushy (simplification/auto-simplify-plushy argmap (:plushy best-individual) (:simplification-steps argmap) error-function (:training-data argmap) (:simplification-k argmap) (:simplification-k-prob argmap) (:simplification-verbose? argmap))]
+              (let [simplified-plushy (simplification/auto-simplify-plushy argmap (:plushy best-individual) (:simplification-steps argmap) error-function (:training-data argmap) (:simplification-k argmap) (:simplification-verbose? argmap))]
                 (prn {:total-test-error-simplified (:total-error (error-function argmap (:testing-data argmap) (hash-map :plushy simplified-plushy)))}))))
         ;;
         (>= generation max-generations)
diff --git a/src/propeller/problems/PSB2/fuel_cost.cljc b/src/propeller/problems/PSB2/fuel_cost.cljc
index 9d45455..9462ebe 100644
--- a/src/propeller/problems/PSB2/fuel_cost.cljc
+++ b/src/propeller/problems/PSB2/fuel_cost.cljc
@@ -1,6 +1,7 @@
 (ns propeller.problems.PSB2.fuel-cost
   (:require [psb2.core :as psb2]
             [propeller.genome :as genome]
+            [propeller.simplification :as simplification]
             [propeller.push.interpreter :as interpreter]
             [propeller.utils :as utils]
             [propeller.push.instructions :refer [get-stack-instructions]]
@@ -81,3 +82,16 @@
        :elitism                 false}
       (apply hash-map (map #(if (string? %) (read-string %) %) args))))
   (#?(:clj shutdown-agents)))
+
+
+(defn fuel-cost-autosimplify
+  [plushy]
+  (simplification/auto-simplify-plushy {:instructions            instructions
+                                        :error-function          error-function
+                                        :training-data           (:train train-and-test-data)
+                                        :testing-data            (:test train-and-test-data)
+                                        :max-generations         300
+                                        :population-size         1000
+                                        :max-initial-plushy-size 250
+                                        :step-limit              2000} plushy 5000 error-function (:train train-and-test-data) 5 true))
+
diff --git a/src/propeller/problems/simple_regression.cljc b/src/propeller/problems/simple_regression.cljc
old mode 100755
new mode 100644
index d0f153e..dd0a063
--- a/src/propeller/problems/simple_regression.cljc
+++ b/src/propeller/problems/simple_regression.cljc
@@ -66,18 +66,25 @@
   [& args]
   (gp/gp
     (merge
-      {:instructions             instructions
-       :error-function           error-function
-       :training-data            (:train train-and-test-data)
-       :testing-data             (:test train-and-test-data)
-       :max-generations          500
-       :population-size          500
-       :max-initial-plushy-size  100
-       :step-limit               200
-       :parent-selection         :lexicase
-       :tournament-size          5
-       :umad-rate                0.1
-       :variation                {:umad 0.5 :crossover 0.5}
-       :elitism                  false}
-      (apply hash-map (map #(if (string? %) (read-string %) %) args))))
+     {:instructions             instructions
+      :error-function           error-function
+      :training-data            (:train train-and-test-data)
+      :testing-data             (:test train-and-test-data)
+      :max-generations          500
+      :population-size          500
+      :max-initial-plushy-size  100
+      :step-limit               200
+      :parent-selection         :lexicase
+      :case-queue?              false
+      :case-step                1
+      :downsample-size          10
+      :tournament-size          5
+      :umad-rate                0.1
+      :variation                {:umad 0.5 :crossover 0.5}
+      :elitism                  false
+      :simplification?          true
+      :simplification-steps     100
+      :simplification-k         5
+      :simplification-verbose?  true}
+     (apply hash-map (map #(if (string? %) (read-string %) %) args))))
   (#?(:clj shutdown-agents)))