| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dicelval1sta.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 2 |  | dicelval1sta.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 3 |  | dicelval1sta.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 4 |  | dicelval1sta.p | ⊢ 𝑃  =  ( ( oc ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 5 |  | dicelval1sta.t | ⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 6 |  | dicelval1sta.i | ⊢ 𝐼  =  ( ( DIsoC ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 7 |  | eqid | ⊢ ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 )  =  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 8 | 1 2 3 4 5 7 6 | dicval | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  →  ( 𝐼 ‘ 𝑄 )  =  { 〈 𝑓 ,  𝑠 〉  ∣  ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) } ) | 
						
							| 9 | 8 | eleq2d | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  →  ( 𝑌  ∈  ( 𝐼 ‘ 𝑄 )  ↔  𝑌  ∈  { 〈 𝑓 ,  𝑠 〉  ∣  ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) } ) ) | 
						
							| 10 | 9 | biimp3a | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 )  ∧  𝑌  ∈  ( 𝐼 ‘ 𝑄 ) )  →  𝑌  ∈  { 〈 𝑓 ,  𝑠 〉  ∣  ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) } ) | 
						
							| 11 |  | eqeq1 | ⊢ ( 𝑓  =  ( 1st  ‘ 𝑌 )  →  ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ↔  ( 1st  ‘ 𝑌 )  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) ) ) ) | 
						
							| 12 | 11 | anbi1d | ⊢ ( 𝑓  =  ( 1st  ‘ 𝑌 )  →  ( ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) )  ↔  ( ( 1st  ‘ 𝑌 )  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) ) ) | 
						
							| 13 |  | fveq1 | ⊢ ( 𝑠  =  ( 2nd  ‘ 𝑌 )  →  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) ) ) | 
						
							| 14 | 13 | eqeq2d | ⊢ ( 𝑠  =  ( 2nd  ‘ 𝑌 )  →  ( ( 1st  ‘ 𝑌 )  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ↔  ( 1st  ‘ 𝑌 )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) ) ) ) | 
						
							| 15 |  | eleq1 | ⊢ ( 𝑠  =  ( 2nd  ‘ 𝑌 )  →  ( 𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 )  ↔  ( 2nd  ‘ 𝑌 )  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) ) | 
						
							| 16 | 14 15 | anbi12d | ⊢ ( 𝑠  =  ( 2nd  ‘ 𝑌 )  →  ( ( ( 1st  ‘ 𝑌 )  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) )  ↔  ( ( 1st  ‘ 𝑌 )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  ( 2nd  ‘ 𝑌 )  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) ) ) | 
						
							| 17 | 12 16 | elopabi | ⊢ ( 𝑌  ∈  { 〈 𝑓 ,  𝑠 〉  ∣  ( 𝑓  =  ( 𝑠 ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  𝑠  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) }  →  ( ( 1st  ‘ 𝑌 )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  ( 2nd  ‘ 𝑌 )  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) ) | 
						
							| 18 | 10 17 | syl | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 )  ∧  𝑌  ∈  ( 𝐼 ‘ 𝑄 ) )  →  ( ( 1st  ‘ 𝑌 )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) )  ∧  ( 2nd  ‘ 𝑌 )  ∈  ( ( TEndo ‘ 𝐾 ) ‘ 𝑊 ) ) ) | 
						
							| 19 | 18 | simpld | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 )  ∧  𝑌  ∈  ( 𝐼 ‘ 𝑄 ) )  →  ( 1st  ‘ 𝑌 )  =  ( ( 2nd  ‘ 𝑌 ) ‘ ( ℩ 𝑔  ∈  𝑇 ( 𝑔 ‘ 𝑃 )  =  𝑄 ) ) ) |