From 2cff512933cc72c7daac4fb09f8a4cc87e8c2562 Mon Sep 17 00:00:00 2001
From: Gaudeval <m.aqpl.c@gmail.com>
Date: Wed, 6 Jan 2021 10:56:05 +0000
Subject: [PATCH 1/3] Fix until output not valued at signal start

---
 mtl/evaluator.py |  6 ++++++
 mtl/test_eval.py | 10 ++++++++++
 2 files changed, 16 insertions(+)

diff --git a/mtl/evaluator.py b/mtl/evaluator.py
index 9650df5..69e0e41 100644
--- a/mtl/evaluator.py
+++ b/mtl/evaluator.py
@@ -33,6 +33,11 @@ def interp(sig, t, tag=None):
     return sig[key][tag]
 
 
+def interp_all(sig, t, end=OO):
+    v = fn.map(lambda u: signal([(t, interp(sig, t, u))], t, end, u), sig.tags)
+    return reduce(op.__or__, v)
+
+
 def dense_compose(sig1, sig2, init=None):
     sig12 = sig1 | sig2
     tags = sig12.tags
@@ -110,6 +115,7 @@ def eval_mtl_until(phi, dt):
 
     def _eval(x):
         sig = dense_compose(f1(x), f2(x), init=-OO)
+        sig = sig | interp_all(sig, x.start, OO)  # Force valuation at start
         data = apply_weak_until(phi.arg1, phi.arg2, sig)
         return signal(data, x.start, OO, tag=phi)
 
diff --git a/mtl/test_eval.py b/mtl/test_eval.py
index dcbb896..9bd3683 100644
--- a/mtl/test_eval.py
+++ b/mtl/test_eval.py
@@ -20,3 +20,13 @@ def test_eval_regression_next_neg():
     v = f(d, quantitative=False, dt=1, time=None)
     assert not f(d, quantitative=False, dt=1)
     assert min(t for t, _ in v) >= 0
+
+
+def test_eval_regression_until_start():
+    """From issue #221"""
+    x = {
+        "ap1": [(0, True), (0.1, True), (0.2, False)],
+    }
+
+    phi = (mtl.parse("(X TRUE W X TRUE)"))
+    phi(x, 0, quantitative=False)

From 927d259fff70813f50440b53c8e913a6f175f3de Mon Sep 17 00:00:00 2001
From: Gaudeval <m.aqpl.c@gmail.com>
Date: Wed, 6 Jan 2021 14:10:58 +0000
Subject: [PATCH 2/3] Add test for missing values in timed until evaluation

---
 mtl/test_eval.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/mtl/test_eval.py b/mtl/test_eval.py
index 09d34fe..3aa6c31 100644
--- a/mtl/test_eval.py
+++ b/mtl/test_eval.py
@@ -42,3 +42,27 @@ def test_eval_regression_until_start():
 
     phi = (mtl.parse("(X TRUE W X TRUE)"))
     phi(x, 0, quantitative=False)
+
+
+def test_eval_regression_timed_until():
+    """From issue #217"""
+    x = {
+        'start': [(0, True), (200, False)],
+        'success': [(0, False), (300, True)]
+    }
+    phi = mtl.parse('(~start U[0,120] success)')
+    assert phi(x, time=200, quantitative=False, dt=1)
+
+    y = {
+        'start': [(0, True), (1, False), (5, True), (6, True)],
+        'success': [(0, False), (20, True)]
+    }
+    phi1 = mtl.parse('(start U[0,20] success)')
+    assert phi1(y, time=6, quantitative=False, dt=1)
+
+    z = {
+        'start': [(0, True), (200, False)],
+        'success': [(0, False), (300, True)]
+    }
+    phi2 = mtl.parse('F[0,120]success')
+    assert phi2(z, time=181, quantitative=False, dt=1)

From c53e490f80f14cde853e8a33c346fe5e474d30a9 Mon Sep 17 00:00:00 2001
From: Gaudeval <m.aqpl.c@gmail.com>
Date: Wed, 6 Jan 2021 14:37:05 +0000
Subject: [PATCH 3/3] Force evaluation of timed always at candidate pivot
 points

---
 mtl/evaluator.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mtl/evaluator.py b/mtl/evaluator.py
index cc3ada1..2af8cc4 100644
--- a/mtl/evaluator.py
+++ b/mtl/evaluator.py
@@ -135,6 +135,12 @@ def _eval(x):
         tmp = f(x)
         assert b >= a
         if b > a:
+            # Force valuation at pivot points
+            if a < b < OO:
+                ts = fn.map(
+                    lambda t: interp_all(tmp, t - b - a + dt, tmp.end),
+                    tmp.times())
+                tmp = reduce(op.__or__, ts, tmp)[tmp.start:tmp.end]
             return tmp.rolling(a, b).map(_min, tag=phi)
 
         return tmp.retag({phi.arg: phi})