codataNotMonotone.err

--- opening "codataNotMonotone.ma" ---
--- scope checking ---
--- type checking ---
type  SNat : + Size -> Set
term  SNat.zero : .[s!ze : Size] -> .[i < s!ze] -> SNat s!ze
term  SNat.zero : .[i : Size] -> < SNat.zero i : SNat $i >
term  SNat.succ : .[s!ze : Size] -> .[i < s!ze] -> ^ SNat i -> SNat s!ze
term  SNat.succ : .[i : Size] -> ^(y1 : SNat i) -> < SNat.succ i y1 : SNat $i >
type  NatEq : -(i : Size) -> ^ SNat i -> ^ SNat i -> Set
term  NatEq.eqz : .[i : Size] -> < NatEq.eqz i : NatEq $i (SNat.zero [i]) (SNat.zero [i]) >
error during typechecking:
NatEq
/// constructor NatEq.eqs
/// szConstructor NatEq : .[i : Size] -> .[n : SNat i] -> .[m : SNat i] -> ^(y3 : NatEq i n m) -> < NatEq.eqs i n m y3 : NatEq $i (SNat.succ [i] n) (SNat.succ [i] m) >
/// new i <= #
/// szSizeVarUsage of i in .[n : SNat i] -> .[m : SNat i] -> ^(y3 : NatEq i n m) -> < NatEq.eqs i n m y3 : NatEq $i (SNat.succ [i] n) (SNat.succ [i] m) >
/// checking SNat i  to be antitone in variable i
/// leqVal'  SNat i  <=-  SNat $i : Set #
/// leqVal'  i  <=-  $i : Size
/// leSize i <=- $i
/// leSize' $i <= i
/// leSize: 0 + 1 <= 0 failed