// your code goes here
const increasingSequence = (arr) => !arr.some((val, idx) => val != arr[0] + idx);
var arr1 = [1, 2, 3, 4];
var arr2 = [1, 2, 4, 5];
var arr3 = [-4, -3, -2, -1];
var arr4 = [-4, -3, -1, 0];
var arr5 = [4, 3, 2, 1, 0];
print(increasingSequence(arr1)); // true
print(increasingSequence(arr2)); // false
print(increasingSequence(arr3)); // true
print(increasingSequence(arr4)); // false
print(increasingSequence(arr5)); // false
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