Detailed syntax breakdown of Definition df-musyn
| Step | Hyp | Ref
 | Expression | 
| 1 |   | cusyn 35554 | 
. 2
class
mUSyn | 
| 2 |   | vt | 
. . 3
setvar 𝑡 | 
| 3 |   | cvv 3464 | 
. . 3
class
V | 
| 4 |   | vv | 
. . . 4
setvar 𝑣 | 
| 5 | 2 | cv 1538 | 
. . . . 5
class 𝑡 | 
| 6 |   | cmuv 35547 | 
. . . . 5
class
mUV | 
| 7 | 5, 6 | cfv 6542 | 
. . . 4
class
(mUV‘𝑡) | 
| 8 | 4 | cv 1538 | 
. . . . . . 7
class 𝑣 | 
| 9 |   | c1st 7995 | 
. . . . . . 7
class
1st | 
| 10 | 8, 9 | cfv 6542 | 
. . . . . 6
class
(1st ‘𝑣) | 
| 11 |   | cmsy 35530 | 
. . . . . . 7
class
mSyn | 
| 12 | 5, 11 | cfv 6542 | 
. . . . . 6
class
(mSyn‘𝑡) | 
| 13 | 10, 12 | cfv 6542 | 
. . . . 5
class
((mSyn‘𝑡)‘(1st ‘𝑣)) | 
| 14 |   | c2nd 7996 | 
. . . . . 6
class
2nd | 
| 15 | 8, 14 | cfv 6542 | 
. . . . 5
class
(2nd ‘𝑣) | 
| 16 | 13, 15 | cop 4614 | 
. . . 4
class
〈((mSyn‘𝑡)‘(1st ‘𝑣)), (2nd ‘𝑣)〉 | 
| 17 | 4, 7, 16 | cmpt 5207 | 
. . 3
class (𝑣 ∈ (mUV‘𝑡) ↦
〈((mSyn‘𝑡)‘(1st ‘𝑣)), (2nd ‘𝑣)〉) | 
| 18 | 2, 3, 17 | cmpt 5207 | 
. 2
class (𝑡 ∈ V ↦ (𝑣 ∈ (mUV‘𝑡) ↦
〈((mSyn‘𝑡)‘(1st ‘𝑣)), (2nd ‘𝑣)〉)) | 
| 19 | 1, 18 | wceq 1539 | 
1
wff mUSyn =
(𝑡 ∈ V ↦ (𝑣 ∈ (mUV‘𝑡) ↦
〈((mSyn‘𝑡)‘(1st ‘𝑣)), (2nd ‘𝑣)〉)) |