 k is just a notation for {0..k
k is just a notation for {0..k }
}
| int_seg | Def {i..j  } == {k:  | i  k  <  j } Thm*  | 
| nat | Def  == {i:  | 0  i } Thm*  | 
| lelt | Def i  j  <  k == i  j  &  j < k | 
| le | Def A  B ==  B < A Thm*  | 
| not | Def  A == A   False Thm*  | 
| surject | Def Surj(A; B; f) ==  b:B.  a:A. f(a) = b Thm*  | 
About:
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