Remove redundant erf(c) rewrites

Author: ricardoV94

aesara/tensor/rewriting/math.py

@@ -2575,8 +2575,6 @@ def local_greedy_distributor(fgraph, node):
 register_stabilize(local_one_plus_erf)
 register_specialize(local_one_plus_erf)
 
-# Only one of the two rewrites below is needed if a canonicalization is added
-# for sub(x, y) -> add(x, -y) or a specialization for add(x, -y) -> sub(x, y)
 # 1-erf(x)=>erfc(x)
 local_one_minus_erf = PatternNodeRewriter(
     (sub, 1, (erf, "x")),
@@ -2590,21 +2588,9 @@ def local_greedy_distributor(fgraph, node):
 register_stabilize(local_one_minus_erf)
 register_specialize(local_one_minus_erf)
 
-local_one_minus_erf2 = PatternNodeRewriter(
-    (add, 1, (neg, (erf, "x"))),
-    (erfc, "x"),
-    allow_multiple_clients=True,
-    name="local_one_minus_erf2",
-    tracks=[erf],
-    get_nodes=get_clients_at_depth2,
-)
-register_canonicalize(local_one_minus_erf2)
-register_stabilize(local_one_minus_erf2)
-register_specialize(local_one_minus_erf2)
-
 # (-1)+erf(x) => -erfc(x)
-# There is no need for erf(x)+(-1) nor erf(x) - 1, as the canonicalize will
-# convert those to the matched pattern
+# There is no need for erf(x)+(-1) nor erf(x) - 1, as the `local_add_mul`
+# canonicalize will convert those to the matched pattern
 local_erf_minus_one = PatternNodeRewriter(
     (add, -1, (erf, "x")),
     (neg, (erfc, "x")),
@@ -2617,8 +2603,6 @@ def local_greedy_distributor(fgraph, node):
 register_stabilize(local_erf_minus_one)
 register_specialize(local_erf_minus_one)
 
-# Only one of the two rewrites below is needed if a canonicalization is added
-# for sub(x, y) -> add(x, -y) or a specialization for add(x, -y) -> sub(x, y)
 # 1-erfc(x) => erf(x)
 local_one_minus_erfc = PatternNodeRewriter(
     (sub, 1, (erfc, "x")),
@@ -2632,21 +2616,9 @@ def local_greedy_distributor(fgraph, node):
 register_stabilize(local_one_minus_erfc)
 register_specialize(local_one_minus_erfc)
 
-local_one_minus_erfc2 = PatternNodeRewriter(
-    (add, 1, (neg, (erfc, "x"))),
-    (erf, "x"),
-    allow_multiple_clients=True,
-    name="local_one_minus_erfc2",
-    tracks=[erfc],
-    get_nodes=get_clients_at_depth2,
-)
-register_canonicalize(local_one_minus_erfc2)
-register_stabilize(local_one_minus_erfc2)
-register_specialize(local_one_minus_erfc2)
-
-# (-1)+erfc(-x)=>erf(x)
+# erfc(-x)-1=>erf(x)
 local_erf_neg_minus_one = PatternNodeRewriter(
-    (add, -1, (erfc, (neg, "x"))),
+    (sub, (erfc, (neg, "x")), 1),
     (erf, "x"),
     allow_multiple_clients=True,
     name="local_erf_neg_minus_one",