diff --git a/README.md b/README.md
index 092b437..db4992b 100644
--- a/README.md
+++ b/README.md
@@ -37,3 +37,13 @@ $ cat helloworld.fs | ./plank
 | e    | exit     | ( -- )         | Exit current function        |
 | L    | lit      | ( -- a )       | Load immediate               |
 | S    | string   | ( -- addr len) | Load string literal          |
+| +    | add      | ( a b -- c )   | c = (a + b)                  |
+| -    | sub      | ( a b -- c )   | c = (a - b)                  |
+| *    | mul      | ( a b -- c )   | c = (a * b)                  |
+| /    | div      | ( a b -- c )   | c = (a / b)                  |
+| %    | mod      | ( a b -- c )   | c = (a % b)                  |
+| &    | and      | ( a b -- c )   | c = (a & b)                  |
+| |    | or       | ( a b -- c )   | c = (a | b)                  |
+| ^    | xor      | ( a b -- c )   | c = (a ^ b)                  |
+| <    | less     | ( a b -- c )   | c = (a < b)                  |
+| =    | equal    | ( a b -- c )   | c = (a == b)                 |
diff --git a/planck.xxd b/planck.xxd
index b63f6b8..39c5e20 100644
--- a/planck.xxd
+++ b/planck.xxd
@@ -6,10 +6,10 @@
 00000028: 3400 2000 0100 0000   e_ehsize,e_phentsize,e_phnum,e_shentsize
 00000030: 0000 0000 0100 0000   e_shnum,e_shstrndx,<phdr> PT_LOAD
 00000038: 0000 0000 0080 0408   p_offset,p_vaddr=0x08048000
-00000040: 0000 0000 0003 0000   p_paddr,p_filesz
+00000040: 0000 0000 0004 0000   p_paddr,p_filesz
 00000048: 0000 0008 0700 0000   p_memsz(128MB),PF_X|PF_W|PF_R
 00000050: 0010 0000 0200 0000   p_align, <here>
-00000058: e082 0408 e880 0408   <latest:init="S">, <interpreter>(5c: key)
+00000058: e082 0408 e880 0408   <latest:init="=">, <interpreter>(5c: key)
 00000060: 6881 0408 9881 0408   (60: find) (64: execute)
 00000068: 3881 0408 f0ff ffff   (68: jump) (6c: -16)
 00000070: be5c 8004 08bd 0080   (70: movl $interpreter,%esi) (75: movl $0x10048000,%ebp)
@@ -117,3 +117,45 @@
 000002e8: ec82 0408 ad56 5001   lodsl; pushl %esi; pushl %eax
 000002f0: c683 c603 83e6 fcad   addl %eax,%esi; addl $3,%esi; andl $~3,%esi;next;
 000002f8: ff20 0000 0000 0000
+
+00000300: e082 0408 012b 0000   +: add
+00000308: 0c83 0408 5801 0424   popl %eax; addl %eax,(%esp)
+00000310: adff 2000 0000 0000   next;
+
+00000318: 0083 0408 012d 0000   -: sub
+00000320: 2483 0408 5829 0424   popl %eax; subl %eax,(%esp)
+00000328: adff 2000 0000 0000   next;
+
+00000330: 1883 0408 012a 0000   *: mul
+00000338: 3c83 0408 585b 0faf   popl %eax; popl %ebx; imul %ebx,%eax
+00000340: c350 adff 2000 0000   pushl %eax; next;
+
+00000348: 3083 0408 012f 0000   /: div
+00000350: 5483 0408 31d2 5b58   xorl %edx,%edx; popl %ebx; popl %eax
+00000358: f7fb 50ad ff20 0000   idiv %ebx; pushl %eax
+
+00000360: 4883 0408 0125 0000   %: mod
+00000368: 6c83 0408 31d2 5b58   xorl %edx,%edx; popl %ebx; popl %eax
+00000370: f7fb 52ad ff20 0000   idiv %ebx; pushl %edx
+
+00000378: 6083 0408 0126 0000   &: and
+00000380: 8483 0408 5821 0424   popl %eax; andl %eax,(%esp)
+00000388: adff 2000 0000 0000   next;
+
+00000390: 7883 0408 017c 0000   |: or
+00000398: 9c83 0408 5809 0424   popl %eax; orl %eax,(%esp)
+000003a0: adff 2000 0000 0000   next;
+
+000003a8: 9083 0408 015e 0000   ^: xor
+000003b0: b483 0408 5831 0424   popl %eax; andl %eax,(%esp)
+000003b8: adff 2000 0000 0000   next;
+
+000003c0: a883 0408 013c 0000   <: less
+000003c8: cc83 0408 585b 39c3   popl %eax; popl %ebx; cmpl %eax,%ebx
+000003d0: 0f9c c00f b6c0 50ad   setl %al; movzbl %al, %eax; pushl %eax; next;
+000003d8: ff20 0000 0000 0000
+
+000003e0: c083 0408 013d 0000   =: equal
+000003e8: ec83 0408 585b 39c3   popl %eax; popl %ebx; cmpl %eax,%ebx
+000003f0: 0f94 c00f b6c0 50ad   setl %al; movzbl %al, %eax; pushl %eax; next;
+000003f8: ff20 0000 0000 0000