
theorem
  or2.<*0,0*>=0 & or2.<*0,1*>=1 & or2.<*1,0*>=1 & or2.<*1,1*>=1 & or2a.
<*0,0*>=1 & or2a.<*0,1*>=1 & or2a.<*1,0*>=0 & or2a.<*1,1*>=1 &
   nand2.<*0,0*>=1 &
  nand2.<*0,1*>=1 & nand2.<*1,0*>=1 & nand2.<*1,1*>=0
proof
  thus or2.<*0,0*> = FALSE 'or' FALSE by FACIRC_1:def 5
    .= 0;
  thus or2.<*0,1*> = FALSE 'or' TRUE by FACIRC_1:def 5
    .= 1;
  thus or2.<*1,0*> = TRUE 'or' FALSE by FACIRC_1:def 5
    .= 1;
  thus or2.<*1,1*> = TRUE 'or' TRUE by FACIRC_1:def 5
    .= 1;
  thus or2a.<*0,0*> = TRUE 'or' FALSE by Def4
    .= 1;
  thus or2a.<*0,1*> = 'not' FALSE 'or' TRUE by Def4
    .= 1;
  thus or2a.<*1,0*> = 'not' TRUE 'or' FALSE by Def4
    .= 0;
  thus or2a.<*1,1*> = 'not' TRUE 'or' TRUE by Def4
    .= 1;
  thus nand2.<*0,0*> = TRUE 'or' 'not' FALSE by Lm2
    .= 1;
  thus nand2.<*0,1*> = TRUE 'or' 'not' TRUE by Lm2
    .= 1;
  thus nand2.<*1,0*> = 'not' TRUE 'or' TRUE by Lm2
    .= 1;
  thus nand2.<*1,1*> = FALSE 'or' 'not' TRUE by Lm2
    .= 0;
end;
