| Mathbox for BJ | 
      
      
      < Previous  
      Next >
      
       Nearby theorems  | 
  ||
| Mirrors > Home > ILE Home > Th. List > Mathboxes > bj-nndcALT | Unicode version | ||
| Description: Alternate proof of nndc 852. (Proof modification is discouraged.) (New usage is discouraged.) (Contributed by BJ, 9-Oct-2019.) | 
| Ref | Expression | 
|---|---|
| bj-nndcALT | 
 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | notnot 630 | 
. . 3
 | |
| 2 | bj-nnor 15380 | 
. . 3
 | |
| 3 | 1, 2 | mpbir 146 | 
. 2
 | 
| 4 | df-dc 836 | 
. . 3
 | |
| 5 | 4 | notbii 669 | 
. 2
 | 
| 6 | 3, 5 | mtbir 672 | 
1
 | 
| Colors of variables: wff set class | 
| Syntax hints:    | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-io 710 | 
| This theorem depends on definitions: df-bi 117 df-dc 836 | 
| This theorem is referenced by: (None) | 
| Copyright terms: Public domain | W3C validator |