Step |
Hyp |
Ref |
Expression |
1 |
|
adds4d.1 |
|
2 |
|
adds4d.2 |
|
3 |
|
adds4d.3 |
|
4 |
|
adds4d.4 |
|
5 |
1 2 3 4
|
adds4d |
Could not format ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( B +s D ) ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( B +s D ) ) ) with typecode |- |
6 |
2 4
|
addscomd |
Could not format ( ph -> ( B +s D ) = ( D +s B ) ) : No typesetting found for |- ( ph -> ( B +s D ) = ( D +s B ) ) with typecode |- |
7 |
6
|
oveq2d |
Could not format ( ph -> ( ( A +s C ) +s ( B +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) : No typesetting found for |- ( ph -> ( ( A +s C ) +s ( B +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) with typecode |- |
8 |
5 7
|
eqtrd |
Could not format ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) with typecode |- |