let T be Ternary_Boolean_Algebra; :: thesis: for a, b, c being Element of T holds Tern (a,b,c) = Tern (c,b,a)

let a, b, c be Element of T; :: thesis: Tern (a,b,c) = Tern (c,b,a)

Tern (a,b,c) = Tern (a,c,b) by Th36a

.= Tern (c,b,a) by Th36b ;

hence Tern (a,b,c) = Tern (c,b,a) ; :: thesis: verum

let a, b, c be Element of T; :: thesis: Tern (a,b,c) = Tern (c,b,a)

Tern (a,b,c) = Tern (a,c,b) by Th36a

.= Tern (c,b,a) by Th36b ;

hence Tern (a,b,c) = Tern (c,b,a) ; :: thesis: verum