## Common Uses

### Default x

One-liner

```   v=: 4 : 'x+y'
v
4 : 'x+y'
(1&\$:) : v
1&\$: :v
(1&\$:) : v f.
1&\$: :(4 : 'x+y')```

Multi-liner

```   w=: 4 : 0
a=. y
x+a
)

(1&\$:) : w f.
1&\$: :(4 : 0)
a=. y
x+a
)```

### Attaching Rank

```   ((1&\$:)"1) : (w"0) f.  NB. both ranks
1&\$:"1 :(4 : 0"0)
a=. y
x+a
)```

Common rank and separate rank

```   w1=: (1&\$:) : w"0 f.
w1
1&\$: :(4 : 0)"0
a=. y
x+a
)
w2=: (1&\$:) : (w"0) f.
w2
1&\$: :(4 : 0"0)
a=. y
x+a
)
w1 b.0
0 0 0
w2 b.0
_ 0 0```

### Attaching Other Conjunctions

Explicit conjunction provides just an ordinary J expression, which can be combined with other conjunctions and trains

Attaching each

```   u=. 3 : 'y+1'&.>
u i.3
+-+-+-+
|1|2|3|
+-+-+-+```

## Uncommon Uses

### Double Explicit

```   z2=: 3 : 0"0 : (4 : 0"0)
a=.y
x+y
)
a=.y
y+1
)
z2
3 : 0"0 :(4 : 0"0)
a=.y
x+y
)
a=.y
y+1
)```
• Order of "declaration" should be monad : dyad, while the order of bodies is dyad ) monad ), because the declaration line is executed from right to left. Thanks to JuneKim for clarification.

### Simultaneous Assignment

Compound declaration can be used in many cases, such as simultaneous assignment

```   '`a b c'=: (4 :0)`(4 :0)`(4 :0)
x+y
)
x-y
)
x*y
)
a
4 : 'x*y'
b
4 : 'x-y'
c
4 : 'x+y'```