Zebra puzzle

You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.



It has several variants, one of them this:

   There are five houses.
   The English man lives in the red house.
   The Swede has a dog.
   The Dane drinks tea.
   The green house is immediately to the left of the white house.
   They drink coffee in the green house.
   The man who smokes Pall Mall has birds.
   In the yellow house they smoke Dunhill.
   In the middle house they drink milk.
   The Norwegian lives in the first house.
   The man who smokes Blend lives in the house next to the house with cats.
   In a house next to the house where they have a horse, they smoke Dunhill.
   The man who smokes Blue Master drinks beer.
   The German smokes Prince.
   The Norwegian lives next to the blue house.
   They drink water in a house next to the house where they smoke Blend. 

The question is, who owns the zebra?

Additionally, list the solution for all the houses.

Optionally, show the solution is unique.



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   Dinesman's multiple-dwelling problem
   Twelve statements


 
# Attempt to unify the input object with the specified object
def unify( object ):
  # Attempt to unify the input object with the specified tag:value
  def unify2(tag; value): 
    if . == null then null
    elif .[tag] == value then .
    elif .[tag] == null then .[tag] = value
    else null 
    end;
  reduce (object|keys[]) as $key
    (.; unify2($key; object[$key]) );
 
# Input: an array
# Output: if the i-th element can be made to satisfy the condition,
# then the updated array, otherwise empty.
def enforce(i; cond):
  if 0 <= i and i < length
  then
    (.[i] | cond) as $ans
    | if $ans then .[i] = $ans else empty end
  else empty
  end ;