is mentioned by

Thm* i,j:, F:({i..j}Prop). (k:{i..j}. Dec(F(k))) Dec(k:{i..j}. F(k))	[decidable__all_int_seg]
Thm* i,j:, F:({i..j}Prop). (k:{i..j}. Dec(F(k))) Dec(k:{i..j}. F(k))	[decidable__ex_int_seg]
Thm* i:, j:{i+1...}, E:({i..j}Prop). E(i) (k:{(i+1)..j}. E(k-1) E(k)) (k:{i..j}. E(k))	[int_seg_ind]
Thm* i:, E:({...i}Prop). E(i) (k:{...i-1}. E(k+1) E(k)) (k:{...i}. E(k))	[int_lower_ind]
Thm* i:, E:({i...}Prop). E(i) (k:{i+1...}. E(k-1) E(k)) (k:{i...}. E(k))	[int_upper_ind]
Thm* P:(Prop). (x:. P(|x|)) (x:. P(x))	[absval_elim]

In prior sections: core well fnd int 1 bool 1

Try larger context: StandardLIB