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 Pack wam_common_lisp -- prolog/wam_cl/compat/utils_higher_order.pl

## Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

complement(+UGraphIn, -UGraphOut)
UGraphOut is a ugraph with an edge between all vertices that are not connected in UGraphIn and all edges from UGraphIn removed. Example:
```?- complement([1-[3,5],2-[4],3-[],
4-[1,2,7,5],5-[],6-[],7-[],8-[]], NL).
NL = [1-[2,4,6,7,8],2-[1,3,5,6,7,8],3-[1,2,4,5,6,7,8],
4-[3,5,6,8],5-[1,2,3,4,6,7,8],6-[1,2,3,4,5,7,8],
7-[1,2,3,4,5,6,8],8-[1,2,3,4,5,6,7]]```
To be done
- Simple two-step algorithm. You could be smarter, I suppose.
partition(:Pred, +List, ?Included, ?Excluded) is det
Filter elements of List according to Pred. True if Included contains all elements for which `call(Pred, X)` succeeds and Excluded contains the remaining elements.
- include/3, exclude/3, partition/5.
foldl(:Goal, +List, +V0, -V)
foldl(:Goal, +List1, +List2, +V0, -V)
foldl(:Goal, +List1, +List2, +List3, +V0, -V)
foldl(:Goal, +List1, +List2, +List3, +List4, +V0, -V)
Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal. The `foldl` family of predicates is defined as follows, with V0 an initial value and V the final value of the folding operation:
```foldl(G, [X_11, ..., X_1n],
[X_21, ..., X_2n],
...,
[X_m1, ..., X_mn], V0, V) :-
call(G, X_11, ..., X_m1, V0, V1),
call(G, X_12, ..., X_m2, V1, V2),
...
call(G, X_1n, ..., X_mn, V<n-1>, V).```

No implementation for a corresponding `foldr` is given. A `foldr` implementation would consist in first calling reverse/2 on each of the m input lists, then applying the appropriate `foldl`. This is actually more efficient than using a properly programmed-out recursive algorithm that cannot be tail-call optimized.

## Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

lpa_apply(Arg1)
lpa_apply(Arg1, Arg2)
identity(Arg1, Arg2)
complement(Arg1)
every(Arg1, Arg2)
some(Arg1, Arg2)
somechk(Arg1, Arg2)
map(Arg1, Arg2, Arg3)
filter(Arg1, Arg2, Arg3)
mapfilter(Arg1, Arg2, Arg3)
foldl1(Arg1, Arg2, Arg3)
foldr(Arg1, Arg2, Arg3, Arg4)
foldr1(Arg1, Arg2, Arg3)