In do-notation

```
a >> b >> c >> d
```

is equivalent to

```
do a
b
c
d
```

(and similarly `a >>= (b >>= (c >>= d))`

is equivalent to

```
do r1 <- a
r2 <- b r1
r3 <- c r2
d r3
```

In do-notation

```
a >> b >> c >> d
```

is equivalent to

```
do a
b
c
d
```

(and similarly `a >>= (b >>= (c >>= d))`

is equivalent to

```
do r1 <- a
r2 <- b r1
r3 <- c r2
d r3
```