Move more code out of Sign and into Main

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

Main.agda

@@ -0,0 +1,25 @@
+module Main where
+
+open import Language
+open import Analysis.Sign
+open import Data.Vec using (Vec; _∷_; [])
+open import IO
+open import Level using (0ℓ)
+
+testCode : Vec Stmt _
+testCode =
+    ("zero" ← (# 0)) ∷
+    ("pos" ← ((` "zero") Expr.+ (# 1))) ∷
+    ("neg" ← ((` "zero") Expr.- (# 1))) ∷
+    ("unknown" ← ((` "pos") Expr.+ (` "neg"))) ∷
+    []
+
+testProgram : Program
+testProgram = record
+    { length = _
+    ; stmts = testCode
+    }
+
+open WithProg testProgram using (output)
+
+main = run {0ℓ} (putStrLn output)