diff --git a/fermi.go b/fermi.go
index c90936e..4033c3a 100644
--- a/fermi.go
+++ b/fermi.go
@@ -357,7 +357,7 @@ func operateDists(old_dist Dist, new_dist Dist, op string) (Dist, error) {
 func parseMixture(words []string, vars map[string]Dist) (Dist, error) {
 	// mx, mix, var weight var weight var weight ...
 	// Check syntax
-	if len(words)%2 != 1 || words[0] != "mx" {
+	if len(words)%2 != 0 {
 		return nil, printAndReturnErr("Not a mixture. \nMixture syntax: \nmx x 2.5 y 8 z 10\ni.e.: mx var weight var2 weight2 ... var_n weight_n")
 	}
 
@@ -365,7 +365,7 @@ func parseMixture(words []string, vars map[string]Dist) (Dist, error) {
 	var fs [][]float64
 	var weights []float64
 
-	for i, word := range words[1:] {
+	for i, word := range words {
 		if i%2 == 0 {
 			dist, exists := vars[word]
 			if !exists {
@@ -400,7 +400,7 @@ func parseWordsIntoOpAndDist(words []string, vars map[string]Dist) (string, Dist
 	var dist Dist
 
 	switch words[0] {
-	case "*", "/", "+", "-":
+	case "*", "/", "+", "-", "mx":
 		op = words[0]
 		words = words[1:]
 	default:
@@ -448,13 +448,14 @@ func parseWordsIntoOpAndDist(words []string, vars map[string]Dist) (string, Dist
 			return parseWordsErr("Input not understood or not implemented yet")
 		}
 	default:
-		switch words[0] {
+		switch op {
 		case "mx":
 			tmp, err := parseMixture(words, vars)
 			if err != nil {
 				return parseWordsErr("Error parsing a mixture: " + err.Error())
 			}
 			dist = tmp
+			op = "*"
 		default:
 			return parseWordsErr("Input not understood or not implemented yet")
 		}
diff --git a/go.mod b/go.mod
index 4ef7fee..1f0aaef 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module git.nunosempere.com/NunoSempere/fermi
 
 go 1.22.1
+
+require github.com/pkg/errors v0.9.1 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..7c401c3
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
diff --git a/mixture.fermi b/mixture.fermi
new file mode 100644
index 0000000..8519b28
--- /dev/null
+++ b/mixture.fermi
@@ -0,0 +1,9 @@
+1 100
+=. x
+
+2K 200K
+=. y
+
+mx x 40% y 60%
+stats
+exit
diff --git a/sample/sample.go b/sample/sample.go
index 7c52ad2..9ed95c8 100644
--- a/sample/sample.go
+++ b/sample/sample.go
@@ -1,6 +1,7 @@
 package sample
 
 import (
+	"fmt"
 	"math"
 	"sync"
 
@@ -180,12 +181,13 @@ func Sample_mixture_serially(fs [][]float64, weights []float64, n_samples int) (
 		return nil, errors.New("Cummulative sum of weights in mixture must be > 0.0")
 	}
 
-	var flag int = 0
-	var p float64 = global_state.Float64()
+	fmt.Printf("Weights: %v\n", cumsummed_normalized_weights)
 
 	xs := make([]float64, n_samples)
 	// var global_state = rand.New(rand.NewPCG(uint64(1), uint64(2)))
 	for i := 0; i < n_samples; i++ {
+		var flag int = 0
+		var p float64 = global_state.Float64()
 		for j, cnw := range cumsummed_normalized_weights {
 			if p < cnw {
 				xs[i] = fs[j][i]