Newer
Older
{
"name": "stdout",
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"text": [
"None\n"
]
}
],
"source": [
"print(unify(expr('Cat(x)'), expr('Dog(Dobby)')))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We also need to take care we do not unintentionally use the same variable name. Unify treats them as a single variable which prevents it from taking multiple value."
]
},
{
"cell_type": "code",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"None\n"
]
}
],
"source": [
"print(unify(expr('Cat(x) & Dog(Dobby)'), expr('Cat(Bella) & Dog(x)')))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Forward Chaining Algorithm\n",
"We consider the simple forward-chaining algorithm presented in <em>Figure 9.3</em>. We look at each rule in the knoweldge base and see if the premises can be satisfied. This is done by finding a substitution which unifies each of the premise with a clause in the `KB`. If we are able to unify the premises, the conclusion (with the corresponding substitution) is added to the `KB`. This inferencing process is repeated until either the query can be answered or till no new sentences can be added. We test if the newly added clause unifies with the query in which case the substitution yielded by `unify` is an answer to the query. If we run out of sentences to infer, this means the query was a failure.\n",
"The function `fol_fc_ask` is a generator which yields all substitutions which validate the query."
]
},
{
"cell_type": "code",
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"metadata": {},
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"\n",
"<div class=\"highlight\"><pre><span></span><span class=\"k\">def</span> <span class=\"nf\">fol_fc_ask</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">alpha</span><span class=\"p\">):</span>\n",
" <span class=\"sd\">"""A simple forward-chaining algorithm. [Figure 9.3]"""</span>\n",
" <span class=\"c1\"># TODO: Improve efficiency</span>\n",
" <span class=\"n\">kb_consts</span> <span class=\"o\">=</span> <span class=\"nb\">list</span><span class=\"p\">({</span><span class=\"n\">c</span> <span class=\"k\">for</span> <span class=\"n\">clause</span> <span class=\"ow\">in</span> <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">clauses</span> <span class=\"k\">for</span> <span class=\"n\">c</span> <span class=\"ow\">in</span> <span class=\"n\">constant_symbols</span><span class=\"p\">(</span><span class=\"n\">clause</span><span class=\"p\">)})</span>\n",
" <span class=\"k\">def</span> <span class=\"nf\">enum_subst</span><span class=\"p\">(</span><span class=\"n\">p</span><span class=\"p\">):</span>\n",
" <span class=\"n\">query_vars</span> <span class=\"o\">=</span> <span class=\"nb\">list</span><span class=\"p\">({</span><span class=\"n\">v</span> <span class=\"k\">for</span> <span class=\"n\">clause</span> <span class=\"ow\">in</span> <span class=\"n\">p</span> <span class=\"k\">for</span> <span class=\"n\">v</span> <span class=\"ow\">in</span> <span class=\"n\">variables</span><span class=\"p\">(</span><span class=\"n\">clause</span><span class=\"p\">)})</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">assignment_list</span> <span class=\"ow\">in</span> <span class=\"n\">itertools</span><span class=\"o\">.</span><span class=\"n\">product</span><span class=\"p\">(</span><span class=\"n\">kb_consts</span><span class=\"p\">,</span> <span class=\"n\">repeat</span><span class=\"o\">=</span><span class=\"nb\">len</span><span class=\"p\">(</span><span class=\"n\">query_vars</span><span class=\"p\">)):</span>\n",
" <span class=\"n\">theta</span> <span class=\"o\">=</span> <span class=\"p\">{</span><span class=\"n\">x</span><span class=\"p\">:</span> <span class=\"n\">y</span> <span class=\"k\">for</span> <span class=\"n\">x</span><span class=\"p\">,</span> <span class=\"n\">y</span> <span class=\"ow\">in</span> <span class=\"nb\">zip</span><span class=\"p\">(</span><span class=\"n\">query_vars</span><span class=\"p\">,</span> <span class=\"n\">assignment_list</span><span class=\"p\">)}</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">theta</span>\n",
"\n",
" <span class=\"c1\"># check if we can answer without new inferences</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">q</span> <span class=\"ow\">in</span> <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">clauses</span><span class=\"p\">:</span>\n",
" <span class=\"n\">phi</span> <span class=\"o\">=</span> <span class=\"n\">unify</span><span class=\"p\">(</span><span class=\"n\">q</span><span class=\"p\">,</span> <span class=\"n\">alpha</span><span class=\"p\">,</span> <span class=\"p\">{})</span>\n",
" <span class=\"k\">if</span> <span class=\"n\">phi</span> <span class=\"ow\">is</span> <span class=\"ow\">not</span> <span class=\"bp\">None</span><span class=\"p\">:</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">phi</span>\n",
"\n",
" <span class=\"k\">while</span> <span class=\"bp\">True</span><span class=\"p\">:</span>\n",
" <span class=\"n\">new</span> <span class=\"o\">=</span> <span class=\"p\">[]</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">rule</span> <span class=\"ow\">in</span> <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">clauses</span><span class=\"p\">:</span>\n",
" <span class=\"n\">p</span><span class=\"p\">,</span> <span class=\"n\">q</span> <span class=\"o\">=</span> <span class=\"n\">parse_definite_clause</span><span class=\"p\">(</span><span class=\"n\">rule</span><span class=\"p\">)</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">theta</span> <span class=\"ow\">in</span> <span class=\"n\">enum_subst</span><span class=\"p\">(</span><span class=\"n\">p</span><span class=\"p\">):</span>\n",
" <span class=\"k\">if</span> <span class=\"nb\">set</span><span class=\"p\">(</span><span class=\"n\">subst</span><span class=\"p\">(</span><span class=\"n\">theta</span><span class=\"p\">,</span> <span class=\"n\">p</span><span class=\"p\">))</span><span class=\"o\">.</span><span class=\"n\">issubset</span><span class=\"p\">(</span><span class=\"nb\">set</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">clauses</span><span class=\"p\">)):</span>\n",
" <span class=\"n\">q_</span> <span class=\"o\">=</span> <span class=\"n\">subst</span><span class=\"p\">(</span><span class=\"n\">theta</span><span class=\"p\">,</span> <span class=\"n\">q</span><span class=\"p\">)</span>\n",
" <span class=\"k\">if</span> <span class=\"nb\">all</span><span class=\"p\">([</span><span class=\"n\">unify</span><span class=\"p\">(</span><span class=\"n\">x</span><span class=\"p\">,</span> <span class=\"n\">q_</span><span class=\"p\">,</span> <span class=\"p\">{})</span> <span class=\"ow\">is</span> <span class=\"bp\">None</span> <span class=\"k\">for</span> <span class=\"n\">x</span> <span class=\"ow\">in</span> <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">clauses</span> <span class=\"o\">+</span> <span class=\"n\">new</span><span class=\"p\">]):</span>\n",
" <span class=\"n\">new</span><span class=\"o\">.</span><span class=\"n\">append</span><span class=\"p\">(</span><span class=\"n\">q_</span><span class=\"p\">)</span>\n",
" <span class=\"n\">phi</span> <span class=\"o\">=</span> <span class=\"n\">unify</span><span class=\"p\">(</span><span class=\"n\">q_</span><span class=\"p\">,</span> <span class=\"n\">alpha</span><span class=\"p\">,</span> <span class=\"p\">{})</span>\n",
" <span class=\"k\">if</span> <span class=\"n\">phi</span> <span class=\"ow\">is</span> <span class=\"ow\">not</span> <span class=\"bp\">None</span><span class=\"p\">:</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">phi</span>\n",
" <span class=\"k\">if</span> <span class=\"ow\">not</span> <span class=\"n\">new</span><span class=\"p\">:</span>\n",
" <span class=\"k\">break</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">clause</span> <span class=\"ow\">in</span> <span class=\"n\">new</span><span class=\"p\">:</span>\n",
" <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">tell</span><span class=\"p\">(</span><span class=\"n\">clause</span><span class=\"p\">)</span>\n",
" <span class=\"k\">return</span> <span class=\"bp\">None</span>\n",
"</pre></div>\n",
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{
"cell_type": "markdown",
"metadata": {},
"source": [
"Let's find out all the hostile nations. Note that we only told the `KB` that Nono was an enemy of America, not that it was hostile."
]
},
{
"cell_type": "code",
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"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"[{x: Nono}]\n"
]
}
],
"source": [
"answer = fol_fc_ask(crime_kb, expr('Hostile(x)'))\n",
"print(list(answer))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"The generator returned a single substitution which says that Nono is a hostile nation. See how after adding another enemy nation the generator returns two substitutions."
]
},
{
"cell_type": "code",
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"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"[{x: Nono}, {x: JaJa}]\n"
]
}
],
"source": [
"crime_kb.tell(expr('Enemy(JaJa, America)'))\n",
"answer = fol_fc_ask(crime_kb, expr('Hostile(x)'))\n",
"print(list(answer))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<strong><em>Note</em>:</strong> `fol_fc_ask` makes changes to the `KB` by adding sentences to it."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Backward Chaining Algorithm\n",
"This algorithm works backward from the goal, chaining through rules to find known facts that support the proof. Suppose `goal` is the query we want to find the substitution for. We find rules of the form $\\text{lhs} \\implies \\text{goal}$ in the `KB` and try to prove `lhs`. There may be multiple clauses in the `KB` which give multiple `lhs`. It is sufficient to prove only one of these. But to prove a `lhs` all the conjuncts in the `lhs` of the clause must be proved. This makes it similar to <em>And/Or</em> search."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### OR\n",
"The <em>OR</em> part of the algorithm comes from our choice to select any clause of the form $\\text{lhs} \\implies \\text{goal}$. Looking at all rules's `lhs` whose `rhs` unify with the `goal`, we yield a substitution which proves all the conjuncts in the `lhs`. We use `parse_definite_clause` to attain `lhs` and `rhs` from a clause of the form $\\text{lhs} \\implies \\text{rhs}$. For atomic facts the `lhs` is an empty list."
]
},
{
"cell_type": "code",
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"execution_count": 87,
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"\n",
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"</head>\n",
"<body>\n",
"<h2></h2>\n",
"\n",
"<div class=\"highlight\"><pre><span></span><span class=\"k\">def</span> <span class=\"nf\">fol_bc_or</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">goal</span><span class=\"p\">,</span> <span class=\"n\">theta</span><span class=\"p\">):</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">rule</span> <span class=\"ow\">in</span> <span class=\"n\">KB</span><span class=\"o\">.</span><span class=\"n\">fetch_rules_for_goal</span><span class=\"p\">(</span><span class=\"n\">goal</span><span class=\"p\">):</span>\n",
" <span class=\"n\">lhs</span><span class=\"p\">,</span> <span class=\"n\">rhs</span> <span class=\"o\">=</span> <span class=\"n\">parse_definite_clause</span><span class=\"p\">(</span><span class=\"n\">standardize_variables</span><span class=\"p\">(</span><span class=\"n\">rule</span><span class=\"p\">))</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">theta1</span> <span class=\"ow\">in</span> <span class=\"n\">fol_bc_and</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">lhs</span><span class=\"p\">,</span> <span class=\"n\">unify</span><span class=\"p\">(</span><span class=\"n\">rhs</span><span class=\"p\">,</span> <span class=\"n\">goal</span><span class=\"p\">,</span> <span class=\"n\">theta</span><span class=\"p\">)):</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">theta1</span>\n",
"</pre></div>\n",
"</body>\n",
"</html>\n"
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"#### AND\n",
"The <em>AND</em> corresponds to proving all the conjuncts in the `lhs`. We need to find a substitution which proves each <em>and</em> every clause in the list of conjuncts."
]
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"\n",
"<div class=\"highlight\"><pre><span></span><span class=\"k\">def</span> <span class=\"nf\">fol_bc_and</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">goals</span><span class=\"p\">,</span> <span class=\"n\">theta</span><span class=\"p\">):</span>\n",
" <span class=\"k\">if</span> <span class=\"n\">theta</span> <span class=\"ow\">is</span> <span class=\"bp\">None</span><span class=\"p\">:</span>\n",
" <span class=\"k\">pass</span>\n",
" <span class=\"k\">elif</span> <span class=\"ow\">not</span> <span class=\"n\">goals</span><span class=\"p\">:</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">theta</span>\n",
" <span class=\"k\">else</span><span class=\"p\">:</span>\n",
" <span class=\"n\">first</span><span class=\"p\">,</span> <span class=\"n\">rest</span> <span class=\"o\">=</span> <span class=\"n\">goals</span><span class=\"p\">[</span><span class=\"mi\">0</span><span class=\"p\">],</span> <span class=\"n\">goals</span><span class=\"p\">[</span><span class=\"mi\">1</span><span class=\"p\">:]</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">theta1</span> <span class=\"ow\">in</span> <span class=\"n\">fol_bc_or</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">subst</span><span class=\"p\">(</span><span class=\"n\">theta</span><span class=\"p\">,</span> <span class=\"n\">first</span><span class=\"p\">),</span> <span class=\"n\">theta</span><span class=\"p\">):</span>\n",
" <span class=\"k\">for</span> <span class=\"n\">theta2</span> <span class=\"ow\">in</span> <span class=\"n\">fol_bc_and</span><span class=\"p\">(</span><span class=\"n\">KB</span><span class=\"p\">,</span> <span class=\"n\">rest</span><span class=\"p\">,</span> <span class=\"n\">theta1</span><span class=\"p\">):</span>\n",
" <span class=\"k\">yield</span> <span class=\"n\">theta2</span>\n",
"</pre></div>\n",
"</body>\n",
"</html>\n"
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"Now the main function `fl_bc_ask` calls `fol_bc_or` with substitution initialized as empty. The `ask` method of `FolKB` uses `fol_bc_ask` and fetches the first substitution returned by the generator to answer query. Let's query the knowledge base we created from `clauses` to find hostile nations."
]
},
{
"cell_type": "code",
"execution_count": 89,
"metadata": {},
"outputs": [],
"source": [
"# Rebuild KB because running fol_fc_ask would add new facts to the KB\n",
"crime_kb = FolKB(clauses)"
]
},
{
"cell_type": "code",
"metadata": {},
"outputs": [
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"data": {
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"{v_5: x, x: Nono}"
]
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"source": [
"crime_kb.ask(expr('Hostile(x)'))"
]
},
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"metadata": {},
"source": [
"You may notice some new variables in the substitution. They are introduced to standardize the variable names to prevent naming problems as discussed in the [Unification section](#Unification)"
]
},
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"cell_type": "markdown",
"metadata": {},
"source": [
"## Appendix: The Implementation of `|'==>'|`\n",
"Consider the `Expr` formed by this syntax:"
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"source": [
"What is the funny `|'==>'|` syntax? The trick is that \"`|`\" is just the regular Python or-operator, and so is exactly equivalent to this: "
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"In other words, there are two applications of or-operators. Here's the first one:"
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"source": [
"What is going on here is that the `__or__` method of `Expr` serves a dual purpose. If the right-hand-side is another `Expr` (or a number), then the result is an `Expr`, as in `(P | Q)`. But if the right-hand-side is a string, then the string is taken to be an operator, and we create a node in the abstract syntax tree corresponding to a partially-filled `Expr`, one where we know the left-hand-side is `P` and the operator is `==>`, but we don't yet know the right-hand-side.\n",
"The `PartialExpr` class has an `__or__` method that says to create an `Expr` node with the right-hand-side filled in. Here we can see the combination of the `PartialExpr` with `Q` to create a complete `Expr`:"
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"partial = PartialExpr('==>', P) \n",
"partial | ~Q"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This [trick](http://code.activestate.com/recipes/384122-infix-operators/) is due to [Ferdinand Jamitzky](http://code.activestate.com/recipes/users/98863/), with a modification by [C. G. Vedant](https://github.com/Chipe1),\n",
"who suggested using a string inside the or-bars.\n",
"\n",
"## Appendix: The Implementation of `expr`\n",
"\n",
"How does `expr` parse a string into an `Expr`? It turns out there are two tricks (besides the Jamitzky/Vedant trick):\n",
"\n",
"1. We do a string substitution, replacing \"`==>`\" with \"`|'==>'|`\" (and likewise for other operators).\n",
"2. We `eval` the resulting string in an environment in which every identifier\n",
"is bound to a symbol with that identifier as the `op`.\n",
"\n",
"In other words,"
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"P, Q = symbols('P, Q')\n",
"~(P & Q) |'==>'| (~P | ~Q)"
]
},
{
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"metadata": {},
"source": [
"One thing to beware of: this puts `==>` at the same precedence level as `\"|\"`, which is not quite right. For example, we get this:"
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"outputs": [
{
"data": {
"text/plain": [
"(((P & Q) ==> P) | Q)"
]
},
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"output_type": "execute_result"
}
],
"source": [
"P & Q |'==>'| P | Q"
]
},
{
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"metadata": {},
"source": [
"which is probably not what we meant; when in doubt, put in extra parens:"
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"((P & Q) ==> (P | Q))"
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"source": [
"(P & Q) |'==>'| (P | Q)"
{
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"source": [
"## Examples"
]
},
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"\n",
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"<div>\n",
"<canvas id=\"canvas_bc_ask\" width=\"800\" height=\"600\" style=\"background:rgba(158, 167, 184, 0.2);\" onclick='click_callback(this, event, \"canvas_bc_ask\")'></canvas>\n",
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"canvas_bc_ask_canvas_object.font(\"12px Arial\");\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(340, 85, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(340, 85, 460, 85);\n",
"canvas_bc_ask_canvas_object.line(340, 85, 340, 115);\n",
"canvas_bc_ask_canvas_object.line(460, 85, 460, 115);\n",
"canvas_bc_ask_canvas_object.line(340, 115, 460, 115);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Criminal(West)\", 348, 109);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(55, 255, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(55, 255, 175, 255);\n",
"canvas_bc_ask_canvas_object.line(55, 255, 55, 285);\n",
"canvas_bc_ask_canvas_object.line(175, 255, 175, 285);\n",
"canvas_bc_ask_canvas_object.line(55, 285, 175, 285);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"American(West)\", 63, 279);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(245, 255, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(245, 255, 365, 255);\n",
"canvas_bc_ask_canvas_object.line(245, 255, 245, 285);\n",
"canvas_bc_ask_canvas_object.line(365, 255, 365, 285);\n",
"canvas_bc_ask_canvas_object.line(245, 285, 365, 285);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Weapon(M1)\", 253, 279);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(435, 255, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(435, 255, 555, 255);\n",
"canvas_bc_ask_canvas_object.line(435, 255, 435, 285);\n",
"canvas_bc_ask_canvas_object.line(555, 255, 555, 285);\n",
"canvas_bc_ask_canvas_object.line(435, 285, 555, 285);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Sells(West, M1, Nono)\", 443, 279);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(625, 255, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(625, 255, 745, 255);\n",
"canvas_bc_ask_canvas_object.line(625, 255, 625, 285);\n",
"canvas_bc_ask_canvas_object.line(745, 255, 745, 285);\n",
"canvas_bc_ask_canvas_object.line(625, 285, 745, 285);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Hostile(Nono)\", 633, 279);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(55, 425, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(55, 425, 175, 425);\n",
"canvas_bc_ask_canvas_object.line(55, 425, 55, 455);\n",
"canvas_bc_ask_canvas_object.line(175, 425, 175, 455);\n",
"canvas_bc_ask_canvas_object.line(55, 455, 175, 455);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Missile(M1)\", 63, 449);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(245, 425, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(245, 425, 365, 425);\n",
"canvas_bc_ask_canvas_object.line(245, 425, 245, 455);\n",
"canvas_bc_ask_canvas_object.line(365, 425, 365, 455);\n",
"canvas_bc_ask_canvas_object.line(245, 455, 365, 455);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Missile(M1)\", 253, 449);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(435, 425, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(435, 425, 555, 425);\n",
"canvas_bc_ask_canvas_object.line(435, 425, 435, 455);\n",
"canvas_bc_ask_canvas_object.line(555, 425, 555, 455);\n",
"canvas_bc_ask_canvas_object.line(435, 455, 555, 455);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Owns(Nono, M1)\", 443, 449);\n",
"canvas_bc_ask_canvas_object.fill(200, 200, 200);\n",
"canvas_bc_ask_canvas_object.rect(625, 425, 120, 30);\n",
"canvas_bc_ask_canvas_object.line(625, 425, 745, 425);\n",
"canvas_bc_ask_canvas_object.line(625, 425, 625, 455);\n",
"canvas_bc_ask_canvas_object.line(745, 425, 745, 455);\n",
"canvas_bc_ask_canvas_object.line(625, 455, 745, 455);\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Enemy(Nono, America)\", 633, 449);\n",
"canvas_bc_ask_canvas_object.line(400, 115, 495, 255);\n",
"canvas_bc_ask_canvas_object.line(305, 285, 115, 425);\n",
"canvas_bc_ask_canvas_object.line(495, 285, 305, 425);\n",
"canvas_bc_ask_canvas_object.line(685, 285, 685, 425);\n",
"canvas_bc_ask_canvas_object.line(400, 115, 685, 255);\n",
"canvas_bc_ask_canvas_object.line(400, 115, 305, 255);\n",
"canvas_bc_ask_canvas_object.line(400, 115, 115, 255);\n",
"canvas_bc_ask_canvas_object.line(495, 285, 495, 425);\n",
"canvas_bc_ask_canvas_object.fill(255, 255, 255);\n",
"canvas_bc_ask_canvas_object.rect(0, 540, 800, 60);\n",
"canvas_bc_ask_canvas_object.strokeWidth(5);\n",
"canvas_bc_ask_canvas_object.stroke(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.line(0, 540, 800, 540);\n",
"canvas_bc_ask_canvas_object.font(\"22px Arial\");\n",
"canvas_bc_ask_canvas_object.fill(0, 0, 0);\n",
"canvas_bc_ask_canvas_object.fill_text(\"Click for text\", 20, 585);\n",
"</script>"
],
"text/plain": [
"<IPython.core.display.HTML object>"
]
},
"metadata": {},
"output_type": "display_data"
}
],
"from notebook import Canvas_fol_bc_ask\n",
"canvas_bc_ask = Canvas_fol_bc_ask('canvas_bc_ask', crime_kb, expr('Criminal(x)'))"
]
},
"metadata": {
"collapsed": true
},
"This notebook by [Chirag Vartak](https://github.com/chiragvartak) and [Peter Norvig](https://github.com/norvig).\n",
}
],
"metadata": {
"kernelspec": {
"language": "python",
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
}
},
"nbformat": 4,