| Step |
Hyp |
Ref |
Expression |
| 1 |
|
hoadd32 |
|- ( ( R : ~H --> ~H /\ S : ~H --> ~H /\ T : ~H --> ~H ) -> ( ( R +op S ) +op T ) = ( ( R +op T ) +op S ) ) |
| 2 |
1
|
oveq1d |
|- ( ( R : ~H --> ~H /\ S : ~H --> ~H /\ T : ~H --> ~H ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( ( R +op T ) +op S ) +op U ) ) |
| 3 |
2
|
3expa |
|- ( ( ( R : ~H --> ~H /\ S : ~H --> ~H ) /\ T : ~H --> ~H ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( ( R +op T ) +op S ) +op U ) ) |
| 4 |
3
|
adantrr |
|- ( ( ( R : ~H --> ~H /\ S : ~H --> ~H ) /\ ( T : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( ( R +op T ) +op S ) +op U ) ) |
| 5 |
|
hoaddcl |
|- ( ( R : ~H --> ~H /\ S : ~H --> ~H ) -> ( R +op S ) : ~H --> ~H ) |
| 6 |
|
hoaddass |
|- ( ( ( R +op S ) : ~H --> ~H /\ T : ~H --> ~H /\ U : ~H --> ~H ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( R +op S ) +op ( T +op U ) ) ) |
| 7 |
6
|
3expb |
|- ( ( ( R +op S ) : ~H --> ~H /\ ( T : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( R +op S ) +op ( T +op U ) ) ) |
| 8 |
5 7
|
sylan |
|- ( ( ( R : ~H --> ~H /\ S : ~H --> ~H ) /\ ( T : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op S ) +op T ) +op U ) = ( ( R +op S ) +op ( T +op U ) ) ) |
| 9 |
|
hoaddcl |
|- ( ( R : ~H --> ~H /\ T : ~H --> ~H ) -> ( R +op T ) : ~H --> ~H ) |
| 10 |
|
hoaddass |
|- ( ( ( R +op T ) : ~H --> ~H /\ S : ~H --> ~H /\ U : ~H --> ~H ) -> ( ( ( R +op T ) +op S ) +op U ) = ( ( R +op T ) +op ( S +op U ) ) ) |
| 11 |
10
|
3expb |
|- ( ( ( R +op T ) : ~H --> ~H /\ ( S : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op T ) +op S ) +op U ) = ( ( R +op T ) +op ( S +op U ) ) ) |
| 12 |
9 11
|
sylan |
|- ( ( ( R : ~H --> ~H /\ T : ~H --> ~H ) /\ ( S : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op T ) +op S ) +op U ) = ( ( R +op T ) +op ( S +op U ) ) ) |
| 13 |
12
|
an4s |
|- ( ( ( R : ~H --> ~H /\ S : ~H --> ~H ) /\ ( T : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( ( R +op T ) +op S ) +op U ) = ( ( R +op T ) +op ( S +op U ) ) ) |
| 14 |
4 8 13
|
3eqtr3d |
|- ( ( ( R : ~H --> ~H /\ S : ~H --> ~H ) /\ ( T : ~H --> ~H /\ U : ~H --> ~H ) ) -> ( ( R +op S ) +op ( T +op U ) ) = ( ( R +op T ) +op ( S +op U ) ) ) |