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Added FreeBASIC
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Qed.
</syntaxhighlight>
=={{header|FreeBASIC}}==
{{trans|Phix}}
<syntaxhighlight lang="vbnet">Type Axioma
r As String
s As String
End Type
Dim Shared axiomas(1 To 6) As Axioma
axiomas(1).r = "even+1": axiomas(1).s = "odd"
axiomas(2).r = "even": axiomas(2).s = "2*int"
axiomas(3).r = "2*int+2*int": axiomas(3).s = "2*(int+int)"
axiomas(4).r = "(int+int)": axiomas(4).s = "int"
axiomas(5).r = "2*int": axiomas(5).s = "even"
axiomas(6).r = "odd": axiomas(6).s = "2*int+1"
Sub Proof(a As String, b As String)
'-- try to convert a into b using only the above axiomas
Dim As String w = a
Dim As String seen() ' -- (avoid infinite loops)
Dim As Integer i, k, hit
Do
Print Using """&"""; w
Redim Preserve seen(Lbound(seen) To Ubound(seen) + 1)
seen(Ubound(seen)) = w
If w = b Then Exit Do
hit = 0
For i = Lbound(axiomas) To Ubound(axiomas)
k = Instr(w, axiomas(i).r)
If k > 0 Then
w = Left(w, k - 1) & axiomas(i).s & Mid(w, k + Len(axiomas(i).r))
hit = i
Exit For
End If
Next i
Print " == ";
Loop Until hit = 0
Print Using "{""&"", ""&"", &}"; a; b; Iif(w = b, "true", "false")
End Sub
Proof("even+even", "even")
Proof("even+1", "odd")
'--bad proofs:
Proof("int", "even")
Sleep</syntaxhighlight>
{{out}}
<pre>"even+even"
== "2*int+even"
== "2*int+2*int"
== "2*(int+int)"
== "2*int"
== "even"
{"even+even", "even", true}
"even+1"
== "odd"
{"even+1", "odd", true}
"int"
{"int", "even", false}</pre>
=={{header|Go}}==
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