|  | Who Cites ground  ptn? | 
|  | 
| ground_ptn | Def ground_ptn(p)
 == Case(p)
 Case ptn_var(v) = > 
 false  Case ptn_pr( < x, y > ) = > 
 ground_ptn(x)   ground_ptn(y)
 Default = >  true  (recursive) | 
 | |  | Thm*  p:Pattern. ground_ptn(p)    | 
|  | 
| case_default | Def Default = >  body(value,value) == body | 
|  | 
| band | Def p   q == if p  q else false  fi | 
 | |  | Thm*  p,q:  . (p   q)    | 
|  | 
| case_lbl_pair | Def Case ptn_pr( < x, y > ) = >  body(x;y) cont(x1,z)
== InjCase(x1; _. cont(z,z); x2.
 InjCase(x2; _. cont(z,z); x2@0. InjCase(x2@0; _. cont(z,z); x2@1. x2@1/x3,x2@2. body(x3;x2@2)))) | 
|  | 
| case_ptn_var | Def Case ptn_var(x) = >  body(x) cont(x1,z)
== (  x1.inr(x2) = > 
 (  x1.inr(x2) = > 
 (  x1.inl(x2) = >  body(hd([x2 / tl(x1)])) cont(hd(x1),z))([x2 / tl(x1)])
 cont
 (hd(x1)
 ,z))
 ([x2 / tl(x1)])
 cont
 (hd(x1)
 ,z))
 ([x1]) | 
|  | 
| case | Def Case(value) body == body(value,value) | 
|  | 
| hd | Def hd(l) == Case of l; nil  "?" ; h.t  h | 
 | |  | Thm*  A:Type, l:A List. ||l||  1   hd(l)  A | 
 | |  | Thm*  A:Type, l:A List  . hd(l)  A | 
|  | 
| tl | Def tl(l) == Case of l; nil  nil ; h.t  t | 
 | |  | Thm*  A:Type, l:A List. tl(l)  A List | 
|  | 
| case_inl | Def inl(x) = >  body(x) cont(value,contvalue)
== InjCase(value; x. body(x); _. cont(contvalue,contvalue)) | 
|  | 
| case_inr | Def inr(x) = >  body(x) cont(value,contvalue)
== InjCase(value; _. cont(contvalue,contvalue); x. body(x)) |