From b179cdf7ecb7ad871df137c41c97889cfcdb5f1d Mon Sep 17 00:00:00 2001
From: Sam Hadow <sam.hadow@inbox.lv>
Date: Fri, 5 Apr 2024 10:53:00 +0200
Subject: [PATCH] begin RAM, pushdown automaton

---
 src/stack.asm | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 src/stack.asm

diff --git a/src/stack.asm b/src/stack.asm
new file mode 100644
index 0000000..7540a8d
--- /dev/null
+++ b/src/stack.asm
@@ -0,0 +1,21 @@
+(5,2,5,5,0)
+ADD(0, 0, r0)       // r0 current state in pushdown automaton
+ADD(2, 0, r1)       // r1 cursor position in input word, (i2 first symbol of input word, i1 length of input word)
+ADD(9, 0, r8)       // r8, address of stack top
+ADD(2, 0, r9)       // r9 bottom symbol
+ADD(i1, 2, r2)      // r2, address first automaton instruction begin state 'q',  instruction: (q, a, A, w, q′)
+ADD(r2, 1, r3)      // r3, address instruction read symbol 'a'
+ADD(r3, 1, r4)      // r4, address instruction read stack symbol 'A'
+ADD(r4, 1, r5)      // r5, address, instruction word pushed on stack length
+ADD(r5, i@r5, r6)
+ADD(1, r6, r6)      // r6, address, next state q'
+
+
+JE(r0, i@r2, )      // current state is the expected state in the instruction
+
+JE(i@r1, 2, )       // read symbol is epsilon
+JE(i@r3, i@r1, )    // symbol in input == read symbol
+JUMP()
+JE(i@r4, 2, )       // read stack symbol is epsilon
+JE(r@r6, i@r4, )    // stack top is the to expected symbol
+