diff --git a/t_list_test.go b/t_list_test.go
index f9e18f6..74c26e2 100644
--- a/t_list_test.go
+++ b/t_list_test.go
@@ -13,18 +13,18 @@ import (
 func TestListParser(t *testing.T) {
 	section := "List"
 
-/*	type inputType struct {
-		source     string
-		wantResult any
-		wantErr    error
-	}
-*/
+	/*	type inputType struct {
+			source     string
+			wantResult any
+			wantErr    error
+		}
+	*/
 	inputs := []inputType{
 		/*   1 */ {`[]`, newListA(), nil},
 		/*   2 */ {`[1,2,3]`, newListA(int64(1), int64(2), int64(3)), nil},
 		/*   3 */ {`[1,2,"hello"]`, newListA(int64(1), int64(2), "hello"), nil},
-		/*   4 */ {`[1+2, not true, "hello"]`, newListA(int64(3), false, "hello"),  nil},
-		/*   5 */ {`[1,2]+[3]`, newListA(int64(1), int64(2), int64(3)),  nil},
+		/*   4 */ {`[1+2, not true, "hello"]`, newListA(int64(3), false, "hello"), nil},
+		/*   5 */ {`[1,2]+[3]`, newListA(int64(1), int64(2), int64(3)), nil},
 		/*   6 */ {`[1,4,3,2]-[3]`, newListA(int64(1), int64(4), int64(2)), nil},
 		/*   7 */ {`add([1,4,3,2])`, int64(10), nil},
 		/*   8 */ {`add([1,[2,2],3,2])`, int64(10), nil},
@@ -52,18 +52,19 @@ func TestListParser(t *testing.T) {
 		/*  30 */ {`2 >> 3;`, nil, errors.New(`[1:4] left operand '2' [integer] and right operand '3' [integer] are not compatible with operator ">>"`)},
 		/*  31 */ {`a=[1,2]; a<<3`, newListA(int64(1), int64(2), int64(3)), nil},
 		/*  33 */ {`a=[1,2]; 5>>a`, newListA(int64(5), int64(1), int64(2)), nil},
-		/*  34 */ {`L=[1,2]; L[0]=9; L`, newListA(int64(9),int64(2)), nil},
+		/*  34 */ {`L=[1,2]; L[0]=9; L`, newListA(int64(9), int64(2)), nil},
 		/*  35 */ {`L=[1,2]; L[5]=9; L`, nil, errors.New(`index 5 out of bounds (0, 1)`)},
 		/*  36 */ {`L=[1,2]; L[]=9; L`, nil, errors.New(`[1:12] index/key specification expected, got [] [list]`)},
+		/*  37 */ {`L=[1,2]; L[nil]=9;`, nil, errors.New(`[1:12] index/key is nil`)},
 		// /*  8 */ {`[int(x)|x=csv("test.csv",1,all(),1)]`, []any{int64(10), int64(40), int64(20)}, nil},
 		// /*  9 */ {`sum(@[int(x)|x=csv("test.csv",1,all(),1)])`, []any{int64(10), int64(40), int64(20)}, nil},
 	}
 
-	        // t.Setenv("EXPR_PATH", ".")
+	// t.Setenv("EXPR_PATH", ".")
 
-        // parserTestSpec(t, section, inputs, 17)
-        parserTest(t, section, inputs)
-return
+	// parserTestSpec(t, section, inputs, 17)
+	parserTest(t, section, inputs)
+	return
 	succeeded := 0
 	failed := 0