% ids refer to https://www.complang.tuwien.ac.at/ulrich/iso-prolog/number_chars_cont

1  ?- number_chars(1.2,"1.2").
      true.

55 ?- number_chars(1.2,"1.20").
      true.

2  ?- number_chars(1.0e9,"1.0E9").
      true.

56 ?- number_chars(1.0e9,"1.0e9").
      true.

64 ?- number_chars(0.0,"-0.0").
      true.

3  ?- number_chars(1,"01").
      true.

65 ?- number_chars(10,"010").
      true.

66 ?- number_chars(N,"010").
      N=10.

67 ?- number_chars(N,"08").
      N=8.

68 ?- number_chars(N,"0b11").
      N=3.

69 ?- number_chars(N,"0o11").
      N=9.

70 ?- number_chars(N,"0x11").
      N=17.

4  ?- number_chars(1,"a").
      syntax_error(...).

5  ?- number_chars(1,[]).
      syntax_error(...).

6  ?- number_chars(1,[[]]).
      type_error(character,[]).

7  ?- number_chars(1,[' ',[]]).
      type_error(character,[]).

8  ?- number_chars(1,[0]).
      type_error(character,0).

9  ?- number_chars(1,[_,[]]).
      type_error(character,[]).

10 ?- number_chars(N,[X]).
      instantiation_error.

11 ?- number_chars(N,['0'|_]).
      instantiation_error.

12 ?- number_chars(N,'1').
      type_error(list,'1').

13 ?- number_chars(N,[a|a]).
      type_error(list,[a|a]).

14 ?- number_chars(N,[49]).
      type_error(character,49).

15 ?- number_chars(N,[]).
      syntax_error(...).

16 ?- number_chars(N,"3 ").
      syntax_error(...).

17 ?- number_chars(N,"3.").
      syntax_error(...).

18 ?- number_chars(N," 1").
      N = 1.

19 ?- number_chars(N,"\n1").
      N = 1.

20 ?- number_chars(N," 0'a").
      N = 0'a. N = 97.

58 ?- number_chars(N,"0'").
      syntax_error(...).

59 ?- number_chars(N,"0'\n").
      syntax_error(...).

60 ?- number_chars(N,"0'\\n").
      N=0'\n. N=10.

61 ?- number_chars(N,"0'\\7\\").
      N=7.

71 ?- number_chars(N,"0'\\7").
      syntax_error(...).

62 ?- number_chars(N,"0'.").
      N=0'. . N = 46.

21 ?- number_chars(N,"- 1").
      N = -1.

54 ?- number_chars(N,"'-'1").
      N = -1.

22 ?- number_chars(N,"/**/1").
      N = 1.

23 ?- number_chars(N,"%\n1").
      N = 1.

57 ?- number_chars(N,"- /**/1").
      N = -1.

24 ?- number_chars(N,"-/**/1").
      syntax_error(...).

63 ?- number_chars(N,"'\\\n-' 3").
      N= -3.

25 ?- number_chars(N,"1e1").
      syntax_error(...).

26 ?- number_chars(N,"1.0e").
      syntax_error(...).

27 ?- number_chars(N,"1.0ee").
      syntax_error(...).

28 ?- number_chars(N,"0x1").
      N = 1.

29 ?- number_chars(N,"0X1").
      syntax_error(...).

30 ?- number_chars(N,"1E1").
      syntax_error(...).

47 ?- number_chars(1,['.'|_]).
      false.

48 ?- number_chars(N,"+1").
      syntax_error(...).

49 ?- number_chars(N,"+ 1").
      syntax_error(...).

50 ?- number_chars(N,"'+'1").
      syntax_error(...).

51 ?- number_chars(N,['11']).
      type_error(character,'11').

52 ?- number_chars(N,['1.1']).
      type_error(character,'1.1').

53 ?- number_chars(1+1,"2").
      type_error(number,1+1).

31 ?- number_chars(1,[C]).
      C = '1'.

32 ?- number_chars(1,[C,D]).
      false.

33 ?- number_chars(1,[C,C]).
      false.

34 ?- number_chars(0,[C,C]).
      false.

35 ?- number_chars(10,[C,D]).
      C = '1', D = '0'.

36 ?- number_chars(100,[C,D]).
      false.

37 ?- number_chars(N,[X|2]).
      type_error(list,[_|2])
   |  instantiation_error.

38 ?- number_chars(N,[1|_]).
      instantiation_error
   |  type_error(character,1).

39 ?- number_chars(V,[1|2]).
      type_error(list,[1|2])
   |  type_error(character,1).

40 ?- number_chars([],1).
      type_error(number,[])
   |  type_error(list,1).

41 ?- number_chars(1,1).
      type_error(list,1).

42 ?- number_chars(1,[a|2]).
      type_error(list,[a|2]).

43 ?- number_chars(1,[_|2]).
      type_error(list,[_|2]).

44 ?- number_chars(1,[[]|_]).
      type_error(character,[]).

45 ?- number_chars(1,[[]|2]).
      type_error(character,[])
   |  type_error(list,[[]|2]).

72 ?- number_chars(V,[1,[],X|2]).
      type_error(list,[1,[],_A|2])
   |  type_error(character,1)
   |  type_error(character,[])
   |  instantiation_error.

46 ?- L=['1'|L], number_chars(N,L).
      sto, ... ; ... .
      sto, type_error(list,['1'|...]) % rational trees
   |  sto, false % occurs-check
   |  sto, representation_error(term)
   |  sto, instantiation_error % literal substitutions
   |  sto, resource_error(...)
   |  sto, loops.