Thm* 'c,'b,'a:S, f:('a 'c), g:('b 'c).
Thm* ( h:(('a+'b) 'c).
Thm* (h o ( x:'a. inl(x)) = f 'a 'c & h o ( x:'b. inr(x)) = g 'b 'c)
Thm* & ( h,y:(('a+'b) 'c).
Thm* & (h o ( x:'a. inl(x)) = f 'a 'c & h o ( x:'b. inr(x)) = g 'b 'c
Thm* & (& y o ( x:'a. inl(x)) = f 'a 'c
Thm* & (& y o ( x:'b. inr(x)) = g 'b 'c
Thm* & (
Thm* & (h = y) | [sum_axiom] |
Thm* 'a,'b:S. all( x:hsum('a; 'b). implies(isr(x),equal(inr(outr(x)),x))) | [hinr_houtr] |
Thm* 'a,'b:S. all( x:hsum('a; 'b). implies(isl(x),equal(inl(outl(x)),x))) | [hinl_houtl] |
Thm* 'a,'b:S. all( x:hsum('a; 'b). or(isl(x),isr(x))) | [hisl_or_isr] |
Thm* 'c,'b,'a:S.
Thm* all
Thm* ( f:'a  'c. all
Thm* ( f:'a  'c. ( g:'b  'c. exists_unique
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. and
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. (all
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. (( x:'a. equal
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. (( x:'a. (h(inl(x))
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. (( x:'a. ,f(x)))
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. ,all
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. ,( x:'b. equal
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. ,( x:'b. (h(inr(x))
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. ,( x:'b. ,g(x))))))) | [hsum_axiom_2] |
Thm* 'c,'b,'a:S.
Thm* all
Thm* ( f:'a  'c. all
Thm* ( f:'a  'c. ( g:'b  'c. exists_unique
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. and
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. (equal(o(h,inl),f)
Thm* ( f:'a  'c. ( g:'b  'c. ( h:hsum('a; 'b)  'c. ,equal(o(h,inr),g))))) | [hsum_axiom] |
Thm* 'b,'a:S. all( x:'b. equal(outr(inr(x)),x)) | [houtr_wd] |
Thm* 'a,'b:S. all( x:'a. equal(outl(inl(x)),x)) | [houtl_wd] |
Thm* 'a,'b:S. and(all( x:'b. isr(inr(x))),all( y:'a. not(isr(inl(y))))) | [hisr_wd] |
Thm* 'b,'a:S. and(all( x:'a. isl(inl(x))),all( y:'b. not(isl(inr(y))))) | [hisl_wd] |
Thm* 'a,'b:S.
Thm* all
Thm* ( e:'b. equal
Thm* ( e:'b. (inr(e)
Thm* ( e:'b. ,abs_sum( b:hbool. x:'a. y:'b. and(equal(y,e),not(b))))) | [hinr_def] |
Thm* 'b,'a:S.
Thm* all
Thm* ( e:'a. equal(inl(e),abs_sum( b:hbool. x:'a. y:'b. and(equal(x,e),b)))) | [hinl_def] |
Thm* 'a,'b:S.
Thm* exists
Thm* ( rep:hsum('a; 'b)  hbool  'a  'b  hbool. type_definition
Thm* ( rep:hsum('a; 'b)  hbool  'a  'b  hbool. (is_sum_rep
Thm* ( rep:hsum('a; 'b)  hbool  'a  'b  hbool. ,rep)) | [hsum_ty_def] |
Thm* 'a,'b:S.
Thm* and
Thm* (all( a:hsum('a; 'b). equal(abs_sum(rep_sum(a)),a))
Thm* ,all
Thm* ,( r:hbool  'a  'b  hbool. equal
Thm* ,( r:hbool  'a  'b  hbool. (is_sum_rep(r)
Thm* ,( r:hbool  'a  'b  hbool. ,equal(rep_sum(abs_sum(r)),r)))) | [hsum_iso_def] |
Thm* 'a,'b:S.
Thm* all
Thm* ( f:hbool
Thm* ( 'a
Thm* ( 'b
Thm* ( hbool. equal
Thm* ( hbool. (is_sum_rep(f)
Thm* ( hbool. ,exists
Thm* ( hbool. ,( v1:'a. exists
Thm* ( hbool. ,( v1:'a. ( v2:'b. or
Thm* ( hbool. ,( v1:'a. ( v2:'b. (equal
Thm* ( hbool. ,( v1:'a. ( v2:'b. ((f
Thm* ( hbool. ,( v1:'a. ( v2:'b. (, b:hbool. x:'a. y:'b. and(equal(x,v1),b))
Thm* ( hbool. ,( v1:'a. ( v2:'b. ,equal
Thm* ( hbool. ,( v1:'a. ( v2:'b. ,(f
Thm* ( hbool. ,( v1:'a. ( v2:'b. ,, b:hbool. x:'a. y:'b. and
Thm* ( hbool. ,( v1:'a. ( v2:'b. ,, b:hbool. x:'a. y:'b. (equal(y,v2)
Thm* ( hbool. ,( v1:'a. ( v2:'b. ,, b:hbool. x:'a. y:'b. ,not(b)))))))) | [his_sum_rep_wd] |
Def outr == u:'a+'b. InjCase(u; x. arb('b), x) | [houtr] |
Def outl == u:'a+'b. InjCase(u; x. x, arb('a)) | [houtl] |
Def isr == u:'a+'b. isr(u) | [hisr] |
Def isl == u:'a+'b. isl(u) | [hisl] |
Def inr == x:'b. inr(x) | [hinr] |
Def inl == x:'a. inl(x) | [hinl] |
Def is_sum_rep == f:  'a 'b  .  u:'a+'b. (f = (rep_sum(u))) | [his_sum_rep] |
Def abs_sum == f:  'a 'b  . @u:'a+'b. (rep_sum(u) = f   'a 'b  ) | [habs_sum] |
Def rep_sum
Def == u:'a+'b. InjCase(u
Def == u:'a+'b. InjCase; p. b: . x:'a. y:'b. (x = p) b
Def == u:'a+'b. InjCase; q. b: . x:'a. y:'b. (y = q)   b) | [hrep_sum] |